diff --git a/cell.go b/cell.go
index 484fb59b..bd4d93be 100644
--- a/cell.go
+++ b/cell.go
@@ -336,7 +336,8 @@ func (f *File) GetCellHyperLink(sheet, axis string) (bool, string, error) {
 // SetCellHyperLink provides a function to set cell hyperlink by given
 // worksheet name and link URL address. LinkType defines two types of
 // hyperlink "External" for web site or "Location" for moving to one of cell
-// in this workbook. The below is example for external link.
+// in this workbook. Maximum limit hyperlinks in a worksheet is 65530. The
+// below is example for external link.
 //
 //    err := f.SetCellHyperLink("Sheet1", "A3", "https://github.com/360EntSecGroup-Skylar/excelize", "External")
 //    // Set underline and font color style for the cell.
@@ -364,6 +365,14 @@ func (f *File) SetCellHyperLink(sheet, axis, link, linkType string) error {
 
 	var linkData xlsxHyperlink
 
+	if xlsx.Hyperlinks == nil {
+		xlsx.Hyperlinks = new(xlsxHyperlinks)
+	}
+
+	if len(xlsx.Hyperlinks.Hyperlink) > 65529 {
+		return errors.New("over maximum limit hyperlinks in a worksheet")
+	}
+
 	switch linkType {
 	case "External":
 		linkData = xlsxHyperlink{
@@ -380,9 +389,6 @@ func (f *File) SetCellHyperLink(sheet, axis, link, linkType string) error {
 		return fmt.Errorf("invalid link type %q", linkType)
 	}
 
-	if xlsx.Hyperlinks == nil {
-		xlsx.Hyperlinks = new(xlsxHyperlinks)
-	}
 	xlsx.Hyperlinks.Hyperlink = append(xlsx.Hyperlinks.Hyperlink, linkData)
 	return nil
 }
diff --git a/chart.go b/chart.go
index c657be8b..d669a473 100644
--- a/chart.go
+++ b/chart.go
@@ -314,16 +314,20 @@ func parseFormatChartSet(formatSet string) (*formatChart, error) {
 //    func main() {
 //        categories := map[string]string{"A2": "Small", "A3": "Normal", "A4": "Large", "B1": "Apple", "C1": "Orange", "D1": "Pear"}
 //        values := map[string]int{"B2": 2, "C2": 3, "D2": 3, "B3": 5, "C3": 2, "D3": 4, "B4": 6, "C4": 7, "D4": 8}
-//        xlsx := excelize.NewFile()
+//        f := excelize.NewFile()
 //        for k, v := range categories {
-//            xlsx.SetCellValue("Sheet1", k, v)
+//            f.SetCellValue("Sheet1", k, v)
 //        }
 //        for k, v := range values {
-//            xlsx.SetCellValue("Sheet1", k, v)
+//            f.SetCellValue("Sheet1", k, v)
+//        }
+//        err := f.AddChart("Sheet1", "E1", `{"type":"col3DClustered","dimension":{"width":640,"height":480},"series":[{"name":"Sheet1!$A$2","categories":"Sheet1!$B$1:$D$1","values":"Sheet1!$B$2:$D$2"},{"name":"Sheet1!$A$3","categories":"Sheet1!$B$1:$D$1","values":"Sheet1!$B$3:$D$3"},{"name":"Sheet1!$A$4","categories":"Sheet1!$B$1:$D$1","values":"Sheet1!$B$4:$D$4"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"bottom","show_legend_key":false},"title":{"name":"Fruit 3D Clustered Column Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero","x_axis":{"reverse_order":true},"y_axis":{"maximum":7.5,"minimum":0.5}}`)
+//        if err != nil {
+//            fmt.Println(err)
+//            return
 //        }
-//        xlsx.AddChart("Sheet1", "E1", `{"type":"col3DClustered","dimension":{"width":640,"height":480},"series":[{"name":"Sheet1!$A$2","categories":"Sheet1!$B$1:$D$1","values":"Sheet1!$B$2:$D$2"},{"name":"Sheet1!$A$3","categories":"Sheet1!$B$1:$D$1","values":"Sheet1!$B$3:$D$3"},{"name":"Sheet1!$A$4","categories":"Sheet1!$B$1:$D$1","values":"Sheet1!$B$4:$D$4"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"bottom","show_legend_key":false},"title":{"name":"Fruit 3D Clustered Column Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero","x_axis":{"reverse_order":true},"y_axis":{"maximum":7.5,"minimum":0.5}}`)
 //        // Save xlsx file by the given path.
-//        err := xlsx.SaveAs("./Book1.xlsx")
+//        err = xlsx.SaveAs("./Book1.xlsx")
 //        if err != nil {
 //            fmt.Println(err)
 //        }
diff --git a/comment.go b/comment.go
index ed3d4a74..79f6fecc 100644
--- a/comment.go
+++ b/comment.go
@@ -72,7 +72,7 @@ func (f *File) getSheetComments(sheetID int) string {
 // author length is 255 and the max text length is 32512. For example, add a
 // comment in Sheet1!$A$30:
 //
-//    err := xlsx.AddComment("Sheet1", "A30", `{"author":"Excelize: ","text":"This is a comment."}`)
+//    err := f.AddComment("Sheet1", "A30", `{"author":"Excelize: ","text":"This is a comment."}`)
 //
 func (f *File) AddComment(sheet, cell, format string) error {
 	formatSet, err := parseFormatCommentsSet(format)
diff --git a/excelize_test.go b/excelize_test.go
index 61921105..87fd8068 100644
--- a/excelize_test.go
+++ b/excelize_test.go
@@ -19,15 +19,15 @@ import (
 
 func TestOpenFile(t *testing.T) {
 	// Test update a XLSX file.
-	xlsx, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
+	f, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
 	// Test get all the rows in a not exists worksheet.
-	xlsx.GetRows("Sheet4")
+	f.GetRows("Sheet4")
 	// Test get all the rows in a worksheet.
-	rows, err := xlsx.GetRows("Sheet2")
+	rows, err := f.GetRows("Sheet2")
 	assert.NoError(t, err)
 	for _, row := range rows {
 		for _, cell := range row {
@@ -35,88 +35,88 @@ func TestOpenFile(t *testing.T) {
 		}
 		t.Log("\r\n")
 	}
-	xlsx.UpdateLinkedValue()
+	f.UpdateLinkedValue()
 
-	xlsx.SetCellDefault("Sheet2", "A1", strconv.FormatFloat(float64(100.1588), 'f', -1, 32))
-	xlsx.SetCellDefault("Sheet2", "A1", strconv.FormatFloat(float64(-100.1588), 'f', -1, 64))
+	f.SetCellDefault("Sheet2", "A1", strconv.FormatFloat(float64(100.1588), 'f', -1, 32))
+	f.SetCellDefault("Sheet2", "A1", strconv.FormatFloat(float64(-100.1588), 'f', -1, 64))
 
 	// Test set cell value with illegal row number.
-	assert.EqualError(t, xlsx.SetCellDefault("Sheet2", "A", strconv.FormatFloat(float64(-100.1588), 'f', -1, 64)),
+	assert.EqualError(t, f.SetCellDefault("Sheet2", "A", strconv.FormatFloat(float64(-100.1588), 'f', -1, 64)),
 		`cannot convert cell "A" to coordinates: invalid cell name "A"`)
 
-	xlsx.SetCellInt("Sheet2", "A1", 100)
+	f.SetCellInt("Sheet2", "A1", 100)
 
 	// Test set cell integer value with illegal row number.
-	assert.EqualError(t, xlsx.SetCellInt("Sheet2", "A", 100), `cannot convert cell "A" to coordinates: invalid cell name "A"`)
+	assert.EqualError(t, f.SetCellInt("Sheet2", "A", 100), `cannot convert cell "A" to coordinates: invalid cell name "A"`)
 
-	xlsx.SetCellStr("Sheet2", "C11", "Knowns")
+	f.SetCellStr("Sheet2", "C11", "Knowns")
 	// Test max characters in a cell.
-	xlsx.SetCellStr("Sheet2", "D11", strings.Repeat("c", 32769))
-	xlsx.NewSheet(":\\/?*[]Maximum 31 characters allowed in sheet title.")
+	f.SetCellStr("Sheet2", "D11", strings.Repeat("c", 32769))
+	f.NewSheet(":\\/?*[]Maximum 31 characters allowed in sheet title.")
 	// Test set worksheet name with illegal name.
-	xlsx.SetSheetName("Maximum 31 characters allowed i", "[Rename]:\\/?* Maximum 31 characters allowed in sheet title.")
-	xlsx.SetCellInt("Sheet3", "A23", 10)
-	xlsx.SetCellStr("Sheet3", "b230", "10")
-	assert.EqualError(t, xlsx.SetCellStr("Sheet10", "b230", "10"), "sheet Sheet10 is not exist")
+	f.SetSheetName("Maximum 31 characters allowed i", "[Rename]:\\/?* Maximum 31 characters allowed in sheet title.")
+	f.SetCellInt("Sheet3", "A23", 10)
+	f.SetCellStr("Sheet3", "b230", "10")
+	assert.EqualError(t, f.SetCellStr("Sheet10", "b230", "10"), "sheet Sheet10 is not exist")
 
 	// Test set cell string value with illegal row number.
-	assert.EqualError(t, xlsx.SetCellStr("Sheet1", "A", "10"), `cannot convert cell "A" to coordinates: invalid cell name "A"`)
+	assert.EqualError(t, f.SetCellStr("Sheet1", "A", "10"), `cannot convert cell "A" to coordinates: invalid cell name "A"`)
 
-	xlsx.SetActiveSheet(2)
+	f.SetActiveSheet(2)
 	// Test get cell formula with given rows number.
-	_, err = xlsx.GetCellFormula("Sheet1", "B19")
+	_, err = f.GetCellFormula("Sheet1", "B19")
 	assert.NoError(t, err)
 	// Test get cell formula with illegal worksheet name.
-	_, err = xlsx.GetCellFormula("Sheet2", "B20")
+	_, err = f.GetCellFormula("Sheet2", "B20")
 	assert.NoError(t, err)
-	_, err = xlsx.GetCellFormula("Sheet1", "B20")
+	_, err = f.GetCellFormula("Sheet1", "B20")
 	assert.NoError(t, err)
 
 	// Test get cell formula with illegal rows number.
-	_, err = xlsx.GetCellFormula("Sheet1", "B")
+	_, err = f.GetCellFormula("Sheet1", "B")
 	assert.EqualError(t, err, `cannot convert cell "B" to coordinates: invalid cell name "B"`)
 	// Test get shared cell formula
-	xlsx.GetCellFormula("Sheet2", "H11")
-	xlsx.GetCellFormula("Sheet2", "I11")
+	f.GetCellFormula("Sheet2", "H11")
+	f.GetCellFormula("Sheet2", "I11")
 	getSharedForumula(&xlsxWorksheet{}, "")
 
 	// Test read cell value with given illegal rows number.
-	_, err = xlsx.GetCellValue("Sheet2", "a-1")
+	_, err = f.GetCellValue("Sheet2", "a-1")
 	assert.EqualError(t, err, `cannot convert cell "A-1" to coordinates: invalid cell name "A-1"`)
-	_, err = xlsx.GetCellValue("Sheet2", "A")
+	_, err = f.GetCellValue("Sheet2", "A")
 	assert.EqualError(t, err, `cannot convert cell "A" to coordinates: invalid cell name "A"`)
 
 	// Test read cell value with given lowercase column number.
-	xlsx.GetCellValue("Sheet2", "a5")
-	xlsx.GetCellValue("Sheet2", "C11")
-	xlsx.GetCellValue("Sheet2", "D11")
-	xlsx.GetCellValue("Sheet2", "D12")
+	f.GetCellValue("Sheet2", "a5")
+	f.GetCellValue("Sheet2", "C11")
+	f.GetCellValue("Sheet2", "D11")
+	f.GetCellValue("Sheet2", "D12")
 	// Test SetCellValue function.
-	assert.NoError(t, xlsx.SetCellValue("Sheet2", "F1", " Hello"))
-	assert.NoError(t, xlsx.SetCellValue("Sheet2", "G1", []byte("World")))
-	assert.NoError(t, xlsx.SetCellValue("Sheet2", "F2", 42))
-	assert.NoError(t, xlsx.SetCellValue("Sheet2", "F3", int8(1<<8/2-1)))
-	assert.NoError(t, xlsx.SetCellValue("Sheet2", "F4", int16(1<<16/2-1)))
-	assert.NoError(t, xlsx.SetCellValue("Sheet2", "F5", int32(1<<32/2-1)))
-	assert.NoError(t, xlsx.SetCellValue("Sheet2", "F6", int64(1<<32/2-1)))
-	assert.NoError(t, xlsx.SetCellValue("Sheet2", "F7", float32(42.65418)))
-	assert.NoError(t, xlsx.SetCellValue("Sheet2", "F8", float64(-42.65418)))
-	assert.NoError(t, xlsx.SetCellValue("Sheet2", "F9", float32(42)))
-	assert.NoError(t, xlsx.SetCellValue("Sheet2", "F10", float64(42)))
-	assert.NoError(t, xlsx.SetCellValue("Sheet2", "F11", uint(1<<32-1)))
-	assert.NoError(t, xlsx.SetCellValue("Sheet2", "F12", uint8(1<<8-1)))
-	assert.NoError(t, xlsx.SetCellValue("Sheet2", "F13", uint16(1<<16-1)))
-	assert.NoError(t, xlsx.SetCellValue("Sheet2", "F14", uint32(1<<32-1)))
-	assert.NoError(t, xlsx.SetCellValue("Sheet2", "F15", uint64(1<<32-1)))
-	assert.NoError(t, xlsx.SetCellValue("Sheet2", "F16", true))
-	assert.NoError(t, xlsx.SetCellValue("Sheet2", "F17", complex64(5+10i)))
+	assert.NoError(t, f.SetCellValue("Sheet2", "F1", " Hello"))
+	assert.NoError(t, f.SetCellValue("Sheet2", "G1", []byte("World")))
+	assert.NoError(t, f.SetCellValue("Sheet2", "F2", 42))
+	assert.NoError(t, f.SetCellValue("Sheet2", "F3", int8(1<<8/2-1)))
+	assert.NoError(t, f.SetCellValue("Sheet2", "F4", int16(1<<16/2-1)))
+	assert.NoError(t, f.SetCellValue("Sheet2", "F5", int32(1<<32/2-1)))
+	assert.NoError(t, f.SetCellValue("Sheet2", "F6", int64(1<<32/2-1)))
+	assert.NoError(t, f.SetCellValue("Sheet2", "F7", float32(42.65418)))
+	assert.NoError(t, f.SetCellValue("Sheet2", "F8", float64(-42.65418)))
+	assert.NoError(t, f.SetCellValue("Sheet2", "F9", float32(42)))
+	assert.NoError(t, f.SetCellValue("Sheet2", "F10", float64(42)))
+	assert.NoError(t, f.SetCellValue("Sheet2", "F11", uint(1<<32-1)))
+	assert.NoError(t, f.SetCellValue("Sheet2", "F12", uint8(1<<8-1)))
+	assert.NoError(t, f.SetCellValue("Sheet2", "F13", uint16(1<<16-1)))
+	assert.NoError(t, f.SetCellValue("Sheet2", "F14", uint32(1<<32-1)))
+	assert.NoError(t, f.SetCellValue("Sheet2", "F15", uint64(1<<32-1)))
+	assert.NoError(t, f.SetCellValue("Sheet2", "F16", true))
+	assert.NoError(t, f.SetCellValue("Sheet2", "F17", complex64(5+10i)))
 
 	// Test on not exists worksheet.
-	assert.EqualError(t, xlsx.SetCellDefault("SheetN", "A1", ""), "sheet SheetN is not exist")
-	assert.EqualError(t, xlsx.SetCellFloat("SheetN", "A1", 42.65418, 2, 32), "sheet SheetN is not exist")
-	assert.EqualError(t, xlsx.SetCellBool("SheetN", "A1", true), "sheet SheetN is not exist")
-	assert.EqualError(t, xlsx.SetCellFormula("SheetN", "A1", ""), "sheet SheetN is not exist")
-	assert.EqualError(t, xlsx.SetCellHyperLink("SheetN", "A1", "Sheet1!A40", "Location"), "sheet SheetN is not exist")
+	assert.EqualError(t, f.SetCellDefault("SheetN", "A1", ""), "sheet SheetN is not exist")
+	assert.EqualError(t, f.SetCellFloat("SheetN", "A1", 42.65418, 2, 32), "sheet SheetN is not exist")
+	assert.EqualError(t, f.SetCellBool("SheetN", "A1", true), "sheet SheetN is not exist")
+	assert.EqualError(t, f.SetCellFormula("SheetN", "A1", ""), "sheet SheetN is not exist")
+	assert.EqualError(t, f.SetCellHyperLink("SheetN", "A1", "Sheet1!A40", "Location"), "sheet SheetN is not exist")
 
 	// Test boolean write
 	booltest := []struct {
@@ -127,55 +127,55 @@ func TestOpenFile(t *testing.T) {
 		{true, "1"},
 	}
 	for _, test := range booltest {
-		xlsx.SetCellValue("Sheet2", "F16", test.value)
-		val, err := xlsx.GetCellValue("Sheet2", "F16")
+		f.SetCellValue("Sheet2", "F16", test.value)
+		val, err := f.GetCellValue("Sheet2", "F16")
 		assert.NoError(t, err)
 		assert.Equal(t, test.expected, val)
 	}
 
-	xlsx.SetCellValue("Sheet2", "G2", nil)
+	f.SetCellValue("Sheet2", "G2", nil)
 
-	assert.EqualError(t, xlsx.SetCellValue("Sheet2", "G4", time.Now()), "only UTC time expected")
+	assert.EqualError(t, f.SetCellValue("Sheet2", "G4", time.Now()), "only UTC time expected")
 
-	xlsx.SetCellValue("Sheet2", "G4", time.Now().UTC())
+	f.SetCellValue("Sheet2", "G4", time.Now().UTC())
 	// 02:46:40
-	xlsx.SetCellValue("Sheet2", "G5", time.Duration(1e13))
+	f.SetCellValue("Sheet2", "G5", time.Duration(1e13))
 	// Test completion column.
-	xlsx.SetCellValue("Sheet2", "M2", nil)
+	f.SetCellValue("Sheet2", "M2", nil)
 	// Test read cell value with given axis large than exists row.
-	xlsx.GetCellValue("Sheet2", "E231")
+	f.GetCellValue("Sheet2", "E231")
 	// Test get active worksheet of XLSX and get worksheet name of XLSX by given worksheet index.
-	xlsx.GetSheetName(xlsx.GetActiveSheetIndex())
+	f.GetSheetName(f.GetActiveSheetIndex())
 	// Test get worksheet index of XLSX by given worksheet name.
-	xlsx.GetSheetIndex("Sheet1")
+	f.GetSheetIndex("Sheet1")
 	// Test get worksheet name of XLSX by given invalid worksheet index.
-	xlsx.GetSheetName(4)
-	// Test get worksheet map of XLSX.
-	xlsx.GetSheetMap()
+	f.GetSheetName(4)
+	// Test get worksheet map of f.
+	f.GetSheetMap()
 	for i := 1; i <= 300; i++ {
-		xlsx.SetCellStr("Sheet3", "c"+strconv.Itoa(i), strconv.Itoa(i))
+		f.SetCellStr("Sheet3", "c"+strconv.Itoa(i), strconv.Itoa(i))
 	}
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestOpenFile.xlsx")))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestOpenFile.xlsx")))
 }
 
 func TestSaveFile(t *testing.T) {
-	xlsx, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
+	f, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestSaveFile.xlsx")))
-	xlsx, err = OpenFile(filepath.Join("test", "TestSaveFile.xlsx"))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestSaveFile.xlsx")))
+	f, err = OpenFile(filepath.Join("test", "TestSaveFile.xlsx"))
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
-	assert.NoError(t, xlsx.Save())
+	assert.NoError(t, f.Save())
 }
 
 func TestSaveAsWrongPath(t *testing.T) {
-	xlsx, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
+	f, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
 	if assert.NoError(t, err) {
 		// Test write file to not exist directory.
-		err = xlsx.SaveAs("")
+		err = f.SaveAs("")
 		if assert.Error(t, err) {
 			assert.True(t, os.IsNotExist(err), "Error: %v: Expected os.IsNotExists(err) == true", err)
 		}
@@ -184,15 +184,15 @@ func TestSaveAsWrongPath(t *testing.T) {
 
 func TestBrokenFile(t *testing.T) {
 	// Test write file with broken file struct.
-	xlsx := File{}
+	f := File{}
 
 	t.Run("SaveWithoutName", func(t *testing.T) {
-		assert.EqualError(t, xlsx.Save(), "no path defined for file, consider File.WriteTo or File.Write")
+		assert.EqualError(t, f.Save(), "no path defined for file, consider File.WriteTo or File.Write")
 	})
 
 	t.Run("SaveAsEmptyStruct", func(t *testing.T) {
 		// Test write file with broken file struct with given path.
-		assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestBrokenFile.SaveAsEmptyStruct.xlsx")))
+		assert.NoError(t, f.SaveAs(filepath.Join("test", "TestBrokenFile.SaveAsEmptyStruct.xlsx")))
 	})
 
 	t.Run("OpenBadWorkbook", func(t *testing.T) {
@@ -214,34 +214,34 @@ func TestBrokenFile(t *testing.T) {
 
 func TestNewFile(t *testing.T) {
 	// Test create a XLSX file.
-	xlsx := NewFile()
-	xlsx.NewSheet("Sheet1")
-	xlsx.NewSheet("XLSXSheet2")
-	xlsx.NewSheet("XLSXSheet3")
-	xlsx.SetCellInt("XLSXSheet2", "A23", 56)
-	xlsx.SetCellStr("Sheet1", "B20", "42")
-	xlsx.SetActiveSheet(0)
+	f := NewFile()
+	f.NewSheet("Sheet1")
+	f.NewSheet("XLSXSheet2")
+	f.NewSheet("XLSXSheet3")
+	f.SetCellInt("XLSXSheet2", "A23", 56)
+	f.SetCellStr("Sheet1", "B20", "42")
+	f.SetActiveSheet(0)
 
 	// Test add picture to sheet with scaling and positioning.
-	err := xlsx.AddPicture("Sheet1", "H2", filepath.Join("test", "images", "excel.gif"),
+	err := f.AddPicture("Sheet1", "H2", filepath.Join("test", "images", "excel.gif"),
 		`{"x_scale": 0.5, "y_scale": 0.5, "positioning": "absolute"}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
 	// Test add picture to worksheet without formatset.
-	err = xlsx.AddPicture("Sheet1", "C2", filepath.Join("test", "images", "excel.png"), "")
+	err = f.AddPicture("Sheet1", "C2", filepath.Join("test", "images", "excel.png"), "")
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
 	// Test add picture to worksheet with invalid formatset.
-	err = xlsx.AddPicture("Sheet1", "C2", filepath.Join("test", "images", "excel.png"), `{`)
+	err = f.AddPicture("Sheet1", "C2", filepath.Join("test", "images", "excel.png"), `{`)
 	if !assert.Error(t, err) {
 		t.FailNow()
 	}
 
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestNewFile.xlsx")))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestNewFile.xlsx")))
 }
 
 func TestColWidth(t *testing.T) {
@@ -275,128 +275,136 @@ func TestAddDrawingVML(t *testing.T) {
 }
 
 func TestSetCellHyperLink(t *testing.T) {
-	xlsx, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
+	f, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
 	if err != nil {
 		t.Log(err)
 	}
 	// Test set cell hyperlink in a work sheet already have hyperlinks.
-	assert.NoError(t, xlsx.SetCellHyperLink("Sheet1", "B19", "https://github.com/360EntSecGroup-Skylar/excelize", "External"))
+	assert.NoError(t, f.SetCellHyperLink("Sheet1", "B19", "https://github.com/360EntSecGroup-Skylar/excelize", "External"))
 	// Test add first hyperlink in a work sheet.
-	assert.NoError(t, xlsx.SetCellHyperLink("Sheet2", "C1", "https://github.com/360EntSecGroup-Skylar/excelize", "External"))
+	assert.NoError(t, f.SetCellHyperLink("Sheet2", "C1", "https://github.com/360EntSecGroup-Skylar/excelize", "External"))
 	// Test add Location hyperlink in a work sheet.
-	assert.NoError(t, xlsx.SetCellHyperLink("Sheet2", "D6", "Sheet1!D8", "Location"))
+	assert.NoError(t, f.SetCellHyperLink("Sheet2", "D6", "Sheet1!D8", "Location"))
 
-	assert.EqualError(t, xlsx.SetCellHyperLink("Sheet2", "C3", "Sheet1!D8", ""), `invalid link type ""`)
+	assert.EqualError(t, f.SetCellHyperLink("Sheet2", "C3", "Sheet1!D8", ""), `invalid link type ""`)
 
-	assert.EqualError(t, xlsx.SetCellHyperLink("Sheet2", "", "Sheet1!D60", "Location"), `invalid cell name ""`)
+	assert.EqualError(t, f.SetCellHyperLink("Sheet2", "", "Sheet1!D60", "Location"), `invalid cell name ""`)
 
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestSetCellHyperLink.xlsx")))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestSetCellHyperLink.xlsx")))
+
+	file := NewFile()
+	for row := 1; row <= 65530; row++ {
+		cell, err := CoordinatesToCellName(1, row)
+		assert.NoError(t, err)
+		assert.NoError(t, file.SetCellHyperLink("Sheet1", cell, "https://github.com/360EntSecGroup-Skylar/excelize", "External"))
+	}
+	assert.EqualError(t, file.SetCellHyperLink("Sheet1", "A65531", "https://github.com/360EntSecGroup-Skylar/excelize", "External"), "over maximum limit hyperlinks in a worksheet")
 }
 
 func TestGetCellHyperLink(t *testing.T) {
-	xlsx, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
+	f, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	_, _, err = xlsx.GetCellHyperLink("Sheet1", "")
+	_, _, err = f.GetCellHyperLink("Sheet1", "")
 	assert.EqualError(t, err, `invalid cell name ""`)
 
-	link, target, err := xlsx.GetCellHyperLink("Sheet1", "A22")
+	link, target, err := f.GetCellHyperLink("Sheet1", "A22")
 	assert.NoError(t, err)
 	t.Log(link, target)
-	link, target, err = xlsx.GetCellHyperLink("Sheet2", "D6")
+	link, target, err = f.GetCellHyperLink("Sheet2", "D6")
 	assert.NoError(t, err)
 	t.Log(link, target)
-	link, target, err = xlsx.GetCellHyperLink("Sheet3", "H3")
+	link, target, err = f.GetCellHyperLink("Sheet3", "H3")
 	assert.EqualError(t, err, "sheet Sheet3 is not exist")
 	t.Log(link, target)
 }
 
 func TestSetCellFormula(t *testing.T) {
-	xlsx, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
+	f, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	xlsx.SetCellFormula("Sheet1", "B19", "SUM(Sheet2!D2,Sheet2!D11)")
-	xlsx.SetCellFormula("Sheet1", "C19", "SUM(Sheet2!D2,Sheet2!D9)")
+	f.SetCellFormula("Sheet1", "B19", "SUM(Sheet2!D2,Sheet2!D11)")
+	f.SetCellFormula("Sheet1", "C19", "SUM(Sheet2!D2,Sheet2!D9)")
 
 	// Test set cell formula with illegal rows number.
-	assert.EqualError(t, xlsx.SetCellFormula("Sheet1", "C", "SUM(Sheet2!D2,Sheet2!D9)"), `cannot convert cell "C" to coordinates: invalid cell name "C"`)
+	assert.EqualError(t, f.SetCellFormula("Sheet1", "C", "SUM(Sheet2!D2,Sheet2!D9)"), `cannot convert cell "C" to coordinates: invalid cell name "C"`)
 
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestSetCellFormula1.xlsx")))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestSetCellFormula1.xlsx")))
 
-	xlsx, err = OpenFile(filepath.Join("test", "CalcChain.xlsx"))
+	f, err = OpenFile(filepath.Join("test", "CalcChain.xlsx"))
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 	// Test remove cell formula.
-	xlsx.SetCellFormula("Sheet1", "A1", "")
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestSetCellFormula2.xlsx")))
+	f.SetCellFormula("Sheet1", "A1", "")
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestSetCellFormula2.xlsx")))
 	// Test remove all cell formula.
-	xlsx.SetCellFormula("Sheet1", "B1", "")
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestSetCellFormula3.xlsx")))
+	f.SetCellFormula("Sheet1", "B1", "")
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestSetCellFormula3.xlsx")))
 }
 
 func TestSetSheetBackground(t *testing.T) {
-	xlsx, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
+	f, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	err = xlsx.SetSheetBackground("Sheet2", filepath.Join("test", "images", "background.jpg"))
+	err = f.SetSheetBackground("Sheet2", filepath.Join("test", "images", "background.jpg"))
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	err = xlsx.SetSheetBackground("Sheet2", filepath.Join("test", "images", "background.jpg"))
+	err = f.SetSheetBackground("Sheet2", filepath.Join("test", "images", "background.jpg"))
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestSetSheetBackground.xlsx")))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestSetSheetBackground.xlsx")))
 }
 
 func TestSetSheetBackgroundErrors(t *testing.T) {
-	xlsx, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
+	f, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	err = xlsx.SetSheetBackground("Sheet2", filepath.Join("test", "not_exists", "not_exists.png"))
+	err = f.SetSheetBackground("Sheet2", filepath.Join("test", "not_exists", "not_exists.png"))
 	if assert.Error(t, err) {
 		assert.True(t, os.IsNotExist(err), "Expected os.IsNotExists(err) == true")
 	}
 
-	err = xlsx.SetSheetBackground("Sheet2", filepath.Join("test", "Book1.xlsx"))
+	err = f.SetSheetBackground("Sheet2", filepath.Join("test", "Book1.xlsx"))
 	assert.EqualError(t, err, "unsupported image extension")
 }
 
 func TestMergeCell(t *testing.T) {
-	xlsx, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
+	f, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	xlsx.MergeCell("Sheet1", "D9", "D9")
-	xlsx.MergeCell("Sheet1", "D9", "E9")
-	xlsx.MergeCell("Sheet1", "H14", "G13")
-	xlsx.MergeCell("Sheet1", "C9", "D8")
-	xlsx.MergeCell("Sheet1", "F11", "G13")
-	xlsx.MergeCell("Sheet1", "H7", "B15")
-	xlsx.MergeCell("Sheet1", "D11", "F13")
-	xlsx.MergeCell("Sheet1", "G10", "K12")
-	xlsx.SetCellValue("Sheet1", "G11", "set value in merged cell")
-	xlsx.SetCellInt("Sheet1", "H11", 100)
-	xlsx.SetCellValue("Sheet1", "I11", float64(0.5))
-	xlsx.SetCellHyperLink("Sheet1", "J11", "https://github.com/360EntSecGroup-Skylar/excelize", "External")
-	xlsx.SetCellFormula("Sheet1", "G12", "SUM(Sheet1!B19,Sheet1!C19)")
-	xlsx.GetCellValue("Sheet1", "H11")
-	xlsx.GetCellValue("Sheet2", "A6") // Merged cell ref is single coordinate.
-	xlsx.GetCellFormula("Sheet1", "G12")
+	f.MergeCell("Sheet1", "D9", "D9")
+	f.MergeCell("Sheet1", "D9", "E9")
+	f.MergeCell("Sheet1", "H14", "G13")
+	f.MergeCell("Sheet1", "C9", "D8")
+	f.MergeCell("Sheet1", "F11", "G13")
+	f.MergeCell("Sheet1", "H7", "B15")
+	f.MergeCell("Sheet1", "D11", "F13")
+	f.MergeCell("Sheet1", "G10", "K12")
+	f.SetCellValue("Sheet1", "G11", "set value in merged cell")
+	f.SetCellInt("Sheet1", "H11", 100)
+	f.SetCellValue("Sheet1", "I11", float64(0.5))
+	f.SetCellHyperLink("Sheet1", "J11", "https://github.com/360EntSecGroup-Skylar/excelize", "External")
+	f.SetCellFormula("Sheet1", "G12", "SUM(Sheet1!B19,Sheet1!C19)")
+	f.GetCellValue("Sheet1", "H11")
+	f.GetCellValue("Sheet2", "A6") // Merged cell ref is single coordinate.
+	f.GetCellFormula("Sheet1", "G12")
 
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestMergeCell.xlsx")))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestMergeCell.xlsx")))
 }
 
 func TestGetMergeCells(t *testing.T) {
@@ -422,13 +430,13 @@ func TestGetMergeCells(t *testing.T) {
 		end:   "C10",
 	}}
 
-	xlsx, err := OpenFile(filepath.Join("test", "MergeCell.xlsx"))
+	f, err := OpenFile(filepath.Join("test", "MergeCell.xlsx"))
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
-	sheet1 := xlsx.GetSheetName(1)
+	sheet1 := f.GetSheetName(1)
 
-	mergeCells, err := xlsx.GetMergeCells(sheet1)
+	mergeCells, err := f.GetMergeCells(sheet1)
 	if !assert.Len(t, mergeCells, len(wants)) {
 		t.FailNow()
 	}
@@ -441,38 +449,38 @@ func TestGetMergeCells(t *testing.T) {
 	}
 
 	// Test get merged cells on not exists worksheet.
-	_, err = xlsx.GetMergeCells("SheetN")
+	_, err = f.GetMergeCells("SheetN")
 	assert.EqualError(t, err, "sheet SheetN is not exist")
 }
 
 func TestSetCellStyleAlignment(t *testing.T) {
-	xlsx, err := prepareTestBook1()
+	f, err := prepareTestBook1()
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
 	var style int
-	style, err = xlsx.NewStyle(`{"alignment":{"horizontal":"center","ident":1,"justify_last_line":true,"reading_order":0,"relative_indent":1,"shrink_to_fit":true,"text_rotation":45,"vertical":"top","wrap_text":true}}`)
+	style, err = f.NewStyle(`{"alignment":{"horizontal":"center","ident":1,"justify_last_line":true,"reading_order":0,"relative_indent":1,"shrink_to_fit":true,"text_rotation":45,"vertical":"top","wrap_text":true}}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	assert.NoError(t, xlsx.SetCellStyle("Sheet1", "A22", "A22", style))
+	assert.NoError(t, f.SetCellStyle("Sheet1", "A22", "A22", style))
 
 	// Test set cell style with given illegal rows number.
-	assert.EqualError(t, xlsx.SetCellStyle("Sheet1", "A", "A22", style), `cannot convert cell "A" to coordinates: invalid cell name "A"`)
-	assert.EqualError(t, xlsx.SetCellStyle("Sheet1", "A22", "A", style), `cannot convert cell "A" to coordinates: invalid cell name "A"`)
+	assert.EqualError(t, f.SetCellStyle("Sheet1", "A", "A22", style), `cannot convert cell "A" to coordinates: invalid cell name "A"`)
+	assert.EqualError(t, f.SetCellStyle("Sheet1", "A22", "A", style), `cannot convert cell "A" to coordinates: invalid cell name "A"`)
 
 	// Test get cell style with given illegal rows number.
-	index, err := xlsx.GetCellStyle("Sheet1", "A")
+	index, err := f.GetCellStyle("Sheet1", "A")
 	assert.Equal(t, 0, index)
 	assert.EqualError(t, err, `cannot convert cell "A" to coordinates: invalid cell name "A"`)
 
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestSetCellStyleAlignment.xlsx")))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestSetCellStyleAlignment.xlsx")))
 }
 
 func TestSetCellStyleBorder(t *testing.T) {
-	xlsx, err := prepareTestBook1()
+	f, err := prepareTestBook1()
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
@@ -480,56 +488,56 @@ func TestSetCellStyleBorder(t *testing.T) {
 	var style int
 
 	// Test set border on overlapping area with vertical variants shading styles gradient fill.
-	style, err = xlsx.NewStyle(`{"border":[{"type":"left","color":"0000FF","style":2},{"type":"top","color":"00FF00","style":12},{"type":"bottom","color":"FFFF00","style":5},{"type":"right","color":"FF0000","style":6},{"type":"diagonalDown","color":"A020F0","style":9},{"type":"diagonalUp","color":"A020F0","style":8}]}`)
+	style, err = f.NewStyle(`{"border":[{"type":"left","color":"0000FF","style":2},{"type":"top","color":"00FF00","style":12},{"type":"bottom","color":"FFFF00","style":5},{"type":"right","color":"FF0000","style":6},{"type":"diagonalDown","color":"A020F0","style":9},{"type":"diagonalUp","color":"A020F0","style":8}]}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
-	assert.NoError(t, xlsx.SetCellStyle("Sheet1", "J21", "L25", style))
+	assert.NoError(t, f.SetCellStyle("Sheet1", "J21", "L25", style))
 
-	style, err = xlsx.NewStyle(`{"border":[{"type":"left","color":"0000FF","style":2},{"type":"top","color":"00FF00","style":3},{"type":"bottom","color":"FFFF00","style":4},{"type":"right","color":"FF0000","style":5},{"type":"diagonalDown","color":"A020F0","style":6},{"type":"diagonalUp","color":"A020F0","style":7}],"fill":{"type":"gradient","color":["#FFFFFF","#E0EBF5"],"shading":1}}`)
+	style, err = f.NewStyle(`{"border":[{"type":"left","color":"0000FF","style":2},{"type":"top","color":"00FF00","style":3},{"type":"bottom","color":"FFFF00","style":4},{"type":"right","color":"FF0000","style":5},{"type":"diagonalDown","color":"A020F0","style":6},{"type":"diagonalUp","color":"A020F0","style":7}],"fill":{"type":"gradient","color":["#FFFFFF","#E0EBF5"],"shading":1}}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
-	assert.NoError(t, xlsx.SetCellStyle("Sheet1", "M28", "K24", style))
+	assert.NoError(t, f.SetCellStyle("Sheet1", "M28", "K24", style))
 
-	style, err = xlsx.NewStyle(`{"border":[{"type":"left","color":"0000FF","style":2},{"type":"top","color":"00FF00","style":3},{"type":"bottom","color":"FFFF00","style":4},{"type":"right","color":"FF0000","style":5},{"type":"diagonalDown","color":"A020F0","style":6},{"type":"diagonalUp","color":"A020F0","style":7}],"fill":{"type":"gradient","color":["#FFFFFF","#E0EBF5"],"shading":4}}`)
+	style, err = f.NewStyle(`{"border":[{"type":"left","color":"0000FF","style":2},{"type":"top","color":"00FF00","style":3},{"type":"bottom","color":"FFFF00","style":4},{"type":"right","color":"FF0000","style":5},{"type":"diagonalDown","color":"A020F0","style":6},{"type":"diagonalUp","color":"A020F0","style":7}],"fill":{"type":"gradient","color":["#FFFFFF","#E0EBF5"],"shading":4}}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
-	assert.NoError(t, xlsx.SetCellStyle("Sheet1", "M28", "K24", style))
+	assert.NoError(t, f.SetCellStyle("Sheet1", "M28", "K24", style))
 
 	// Test set border and solid style pattern fill for a single cell.
-	style, err = xlsx.NewStyle(`{"border":[{"type":"left","color":"0000FF","style":8},{"type":"top","color":"00FF00","style":9},{"type":"bottom","color":"FFFF00","style":10},{"type":"right","color":"FF0000","style":11},{"type":"diagonalDown","color":"A020F0","style":12},{"type":"diagonalUp","color":"A020F0","style":13}],"fill":{"type":"pattern","color":["#E0EBF5"],"pattern":1}}`)
+	style, err = f.NewStyle(`{"border":[{"type":"left","color":"0000FF","style":8},{"type":"top","color":"00FF00","style":9},{"type":"bottom","color":"FFFF00","style":10},{"type":"right","color":"FF0000","style":11},{"type":"diagonalDown","color":"A020F0","style":12},{"type":"diagonalUp","color":"A020F0","style":13}],"fill":{"type":"pattern","color":["#E0EBF5"],"pattern":1}}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	assert.NoError(t, xlsx.SetCellStyle("Sheet1", "O22", "O22", style))
+	assert.NoError(t, f.SetCellStyle("Sheet1", "O22", "O22", style))
 
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestSetCellStyleBorder.xlsx")))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestSetCellStyleBorder.xlsx")))
 }
 
 func TestSetCellStyleBorderErrors(t *testing.T) {
-	xlsx, err := prepareTestBook1()
+	f, err := prepareTestBook1()
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
 	// Set border with invalid style parameter.
-	_, err = xlsx.NewStyle("")
+	_, err = f.NewStyle("")
 	if !assert.EqualError(t, err, "unexpected end of JSON input") {
 		t.FailNow()
 	}
 
 	// Set border with invalid style index number.
-	_, err = xlsx.NewStyle(`{"border":[{"type":"left","color":"0000FF","style":-1},{"type":"top","color":"00FF00","style":14},{"type":"bottom","color":"FFFF00","style":5},{"type":"right","color":"FF0000","style":6},{"type":"diagonalDown","color":"A020F0","style":9},{"type":"diagonalUp","color":"A020F0","style":8}]}`)
+	_, err = f.NewStyle(`{"border":[{"type":"left","color":"0000FF","style":-1},{"type":"top","color":"00FF00","style":14},{"type":"bottom","color":"FFFF00","style":5},{"type":"right","color":"FF0000","style":6},{"type":"diagonalDown","color":"A020F0","style":9},{"type":"diagonalUp","color":"A020F0","style":8}]}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 }
 
 func TestSetCellStyleNumberFormat(t *testing.T) {
-	xlsx, err := prepareTestBook1()
+	f, err := prepareTestBook1()
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
@@ -544,202 +552,202 @@ func TestSetCellStyleNumberFormat(t *testing.T) {
 			var val float64
 			val, err = strconv.ParseFloat(v, 64)
 			if err != nil {
-				xlsx.SetCellValue("Sheet2", c, v)
+				f.SetCellValue("Sheet2", c, v)
 			} else {
-				xlsx.SetCellValue("Sheet2", c, val)
+				f.SetCellValue("Sheet2", c, val)
 			}
-			style, err := xlsx.NewStyle(`{"fill":{"type":"gradient","color":["#FFFFFF","#E0EBF5"],"shading":5},"number_format": ` + strconv.Itoa(d) + `}`)
+			style, err := f.NewStyle(`{"fill":{"type":"gradient","color":["#FFFFFF","#E0EBF5"],"shading":5},"number_format": ` + strconv.Itoa(d) + `}`)
 			if !assert.NoError(t, err) {
 				t.FailNow()
 			}
-			assert.NoError(t, xlsx.SetCellStyle("Sheet2", c, c, style))
-			t.Log(xlsx.GetCellValue("Sheet2", c))
+			assert.NoError(t, f.SetCellStyle("Sheet2", c, c, style))
+			t.Log(f.GetCellValue("Sheet2", c))
 		}
 	}
 	var style int
-	style, err = xlsx.NewStyle(`{"number_format":-1}`)
+	style, err = f.NewStyle(`{"number_format":-1}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
-	assert.NoError(t, xlsx.SetCellStyle("Sheet2", "L33", "L33", style))
+	assert.NoError(t, f.SetCellStyle("Sheet2", "L33", "L33", style))
 
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestSetCellStyleNumberFormat.xlsx")))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestSetCellStyleNumberFormat.xlsx")))
 }
 
 func TestSetCellStyleCurrencyNumberFormat(t *testing.T) {
 	t.Run("TestBook3", func(t *testing.T) {
-		xlsx, err := prepareTestBook3()
+		f, err := prepareTestBook3()
 		if !assert.NoError(t, err) {
 			t.FailNow()
 		}
 
-		xlsx.SetCellValue("Sheet1", "A1", 56)
-		xlsx.SetCellValue("Sheet1", "A2", -32.3)
+		f.SetCellValue("Sheet1", "A1", 56)
+		f.SetCellValue("Sheet1", "A2", -32.3)
 		var style int
-		style, err = xlsx.NewStyle(`{"number_format": 188, "decimal_places": -1}`)
+		style, err = f.NewStyle(`{"number_format": 188, "decimal_places": -1}`)
 		if !assert.NoError(t, err) {
 			t.FailNow()
 		}
 
-		assert.NoError(t, xlsx.SetCellStyle("Sheet1", "A1", "A1", style))
-		style, err = xlsx.NewStyle(`{"number_format": 188, "decimal_places": 31, "negred": true}`)
+		assert.NoError(t, f.SetCellStyle("Sheet1", "A1", "A1", style))
+		style, err = f.NewStyle(`{"number_format": 188, "decimal_places": 31, "negred": true}`)
 		if !assert.NoError(t, err) {
 			t.FailNow()
 		}
 
-		assert.NoError(t, xlsx.SetCellStyle("Sheet1", "A2", "A2", style))
+		assert.NoError(t, f.SetCellStyle("Sheet1", "A2", "A2", style))
 
-		assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestSetCellStyleCurrencyNumberFormat.TestBook3.xlsx")))
+		assert.NoError(t, f.SaveAs(filepath.Join("test", "TestSetCellStyleCurrencyNumberFormat.TestBook3.xlsx")))
 	})
 
 	t.Run("TestBook4", func(t *testing.T) {
-		xlsx, err := prepareTestBook4()
+		f, err := prepareTestBook4()
 		if !assert.NoError(t, err) {
 			t.FailNow()
 		}
-		xlsx.SetCellValue("Sheet1", "A1", 42920.5)
-		xlsx.SetCellValue("Sheet1", "A2", 42920.5)
+		f.SetCellValue("Sheet1", "A1", 42920.5)
+		f.SetCellValue("Sheet1", "A2", 42920.5)
 
-		_, err = xlsx.NewStyle(`{"number_format": 26, "lang": "zh-tw"}`)
+		_, err = f.NewStyle(`{"number_format": 26, "lang": "zh-tw"}`)
 		if !assert.NoError(t, err) {
 			t.FailNow()
 		}
 
-		style, err := xlsx.NewStyle(`{"number_format": 27}`)
+		style, err := f.NewStyle(`{"number_format": 27}`)
 		if !assert.NoError(t, err) {
 			t.FailNow()
 		}
 
-		assert.NoError(t, xlsx.SetCellStyle("Sheet1", "A1", "A1", style))
-		style, err = xlsx.NewStyle(`{"number_format": 31, "lang": "ko-kr"}`)
+		assert.NoError(t, f.SetCellStyle("Sheet1", "A1", "A1", style))
+		style, err = f.NewStyle(`{"number_format": 31, "lang": "ko-kr"}`)
 		if !assert.NoError(t, err) {
 			t.FailNow()
 		}
 
-		assert.NoError(t, xlsx.SetCellStyle("Sheet1", "A2", "A2", style))
+		assert.NoError(t, f.SetCellStyle("Sheet1", "A2", "A2", style))
 
-		style, err = xlsx.NewStyle(`{"number_format": 71, "lang": "th-th"}`)
+		style, err = f.NewStyle(`{"number_format": 71, "lang": "th-th"}`)
 		if !assert.NoError(t, err) {
 			t.FailNow()
 		}
-		assert.NoError(t, xlsx.SetCellStyle("Sheet1", "A2", "A2", style))
+		assert.NoError(t, f.SetCellStyle("Sheet1", "A2", "A2", style))
 
-		assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestSetCellStyleCurrencyNumberFormat.TestBook4.xlsx")))
+		assert.NoError(t, f.SaveAs(filepath.Join("test", "TestSetCellStyleCurrencyNumberFormat.TestBook4.xlsx")))
 	})
 }
 
 func TestSetCellStyleCustomNumberFormat(t *testing.T) {
-	xlsx := NewFile()
-	xlsx.SetCellValue("Sheet1", "A1", 42920.5)
-	xlsx.SetCellValue("Sheet1", "A2", 42920.5)
-	style, err := xlsx.NewStyle(`{"custom_number_format": "[$-380A]dddd\\,\\ dd\" de \"mmmm\" de \"yyyy;@"}`)
+	f := NewFile()
+	f.SetCellValue("Sheet1", "A1", 42920.5)
+	f.SetCellValue("Sheet1", "A2", 42920.5)
+	style, err := f.NewStyle(`{"custom_number_format": "[$-380A]dddd\\,\\ dd\" de \"mmmm\" de \"yyyy;@"}`)
 	if err != nil {
 		t.Log(err)
 	}
-	assert.NoError(t, xlsx.SetCellStyle("Sheet1", "A1", "A1", style))
-	style, err = xlsx.NewStyle(`{"custom_number_format": "[$-380A]dddd\\,\\ dd\" de \"mmmm\" de \"yyyy;@"}`)
+	assert.NoError(t, f.SetCellStyle("Sheet1", "A1", "A1", style))
+	style, err = f.NewStyle(`{"custom_number_format": "[$-380A]dddd\\,\\ dd\" de \"mmmm\" de \"yyyy;@"}`)
 	if err != nil {
 		t.Log(err)
 	}
-	assert.NoError(t, xlsx.SetCellStyle("Sheet1", "A2", "A2", style))
+	assert.NoError(t, f.SetCellStyle("Sheet1", "A2", "A2", style))
 
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestSetCellStyleCustomNumberFormat.xlsx")))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestSetCellStyleCustomNumberFormat.xlsx")))
 }
 
 func TestSetCellStyleFill(t *testing.T) {
-	xlsx, err := prepareTestBook1()
+	f, err := prepareTestBook1()
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
 	var style int
 	// Test set fill for cell with invalid parameter.
-	style, err = xlsx.NewStyle(`{"fill":{"type":"gradient","color":["#FFFFFF","#E0EBF5"],"shading":6}}`)
+	style, err = f.NewStyle(`{"fill":{"type":"gradient","color":["#FFFFFF","#E0EBF5"],"shading":6}}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
-	assert.NoError(t, xlsx.SetCellStyle("Sheet1", "O23", "O23", style))
+	assert.NoError(t, f.SetCellStyle("Sheet1", "O23", "O23", style))
 
-	style, err = xlsx.NewStyle(`{"fill":{"type":"gradient","color":["#FFFFFF"],"shading":1}}`)
+	style, err = f.NewStyle(`{"fill":{"type":"gradient","color":["#FFFFFF"],"shading":1}}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
-	assert.NoError(t, xlsx.SetCellStyle("Sheet1", "O23", "O23", style))
+	assert.NoError(t, f.SetCellStyle("Sheet1", "O23", "O23", style))
 
-	style, err = xlsx.NewStyle(`{"fill":{"type":"pattern","color":[],"pattern":1}}`)
+	style, err = f.NewStyle(`{"fill":{"type":"pattern","color":[],"pattern":1}}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
-	assert.NoError(t, xlsx.SetCellStyle("Sheet1", "O23", "O23", style))
+	assert.NoError(t, f.SetCellStyle("Sheet1", "O23", "O23", style))
 
-	style, err = xlsx.NewStyle(`{"fill":{"type":"pattern","color":["#E0EBF5"],"pattern":19}}`)
+	style, err = f.NewStyle(`{"fill":{"type":"pattern","color":["#E0EBF5"],"pattern":19}}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
-	assert.NoError(t, xlsx.SetCellStyle("Sheet1", "O23", "O23", style))
+	assert.NoError(t, f.SetCellStyle("Sheet1", "O23", "O23", style))
 
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestSetCellStyleFill.xlsx")))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestSetCellStyleFill.xlsx")))
 }
 
 func TestSetCellStyleFont(t *testing.T) {
-	xlsx, err := prepareTestBook1()
+	f, err := prepareTestBook1()
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
 	var style int
-	style, err = xlsx.NewStyle(`{"font":{"bold":true,"italic":true,"family":"Berlin Sans FB Demi","size":36,"color":"#777777","underline":"single"}}`)
+	style, err = f.NewStyle(`{"font":{"bold":true,"italic":true,"family":"Berlin Sans FB Demi","size":36,"color":"#777777","underline":"single"}}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	assert.NoError(t, xlsx.SetCellStyle("Sheet2", "A1", "A1", style))
+	assert.NoError(t, f.SetCellStyle("Sheet2", "A1", "A1", style))
 
-	style, err = xlsx.NewStyle(`{"font":{"italic":true,"underline":"double"}}`)
+	style, err = f.NewStyle(`{"font":{"italic":true,"underline":"double"}}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	assert.NoError(t, xlsx.SetCellStyle("Sheet2", "A2", "A2", style))
+	assert.NoError(t, f.SetCellStyle("Sheet2", "A2", "A2", style))
 
-	style, err = xlsx.NewStyle(`{"font":{"bold":true}}`)
+	style, err = f.NewStyle(`{"font":{"bold":true}}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	assert.NoError(t, xlsx.SetCellStyle("Sheet2", "A3", "A3", style))
+	assert.NoError(t, f.SetCellStyle("Sheet2", "A3", "A3", style))
 
-	style, err = xlsx.NewStyle(`{"font":{"bold":true,"family":"","size":0,"color":"","underline":""}}`)
+	style, err = f.NewStyle(`{"font":{"bold":true,"family":"","size":0,"color":"","underline":""}}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	assert.NoError(t, xlsx.SetCellStyle("Sheet2", "A4", "A4", style))
+	assert.NoError(t, f.SetCellStyle("Sheet2", "A4", "A4", style))
 
-	style, err = xlsx.NewStyle(`{"font":{"color":"#777777"}}`)
+	style, err = f.NewStyle(`{"font":{"color":"#777777"}}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	assert.NoError(t, xlsx.SetCellStyle("Sheet2", "A5", "A5", style))
+	assert.NoError(t, f.SetCellStyle("Sheet2", "A5", "A5", style))
 
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestSetCellStyleFont.xlsx")))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestSetCellStyleFont.xlsx")))
 }
 
 func TestSetCellStyleProtection(t *testing.T) {
-	xlsx, err := prepareTestBook1()
+	f, err := prepareTestBook1()
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
 	var style int
-	style, err = xlsx.NewStyle(`{"protection":{"hidden":true, "locked":true}}`)
+	style, err = f.NewStyle(`{"protection":{"hidden":true, "locked":true}}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	assert.NoError(t, xlsx.SetCellStyle("Sheet2", "A6", "A6", style))
-	err = xlsx.SaveAs(filepath.Join("test", "TestSetCellStyleProtection.xlsx"))
+	assert.NoError(t, f.SetCellStyle("Sheet2", "A6", "A6", style))
+	err = f.SaveAs(filepath.Join("test", "TestSetCellStyleProtection.xlsx"))
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
@@ -747,172 +755,172 @@ func TestSetCellStyleProtection(t *testing.T) {
 
 func TestSetDeleteSheet(t *testing.T) {
 	t.Run("TestBook3", func(t *testing.T) {
-		xlsx, err := prepareTestBook3()
+		f, err := prepareTestBook3()
 		if !assert.NoError(t, err) {
 			t.FailNow()
 		}
 
-		xlsx.DeleteSheet("XLSXSheet3")
-		assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestSetDeleteSheet.TestBook3.xlsx")))
+		f.DeleteSheet("XLSXSheet3")
+		assert.NoError(t, f.SaveAs(filepath.Join("test", "TestSetDeleteSheet.TestBook3.xlsx")))
 	})
 
 	t.Run("TestBook4", func(t *testing.T) {
-		xlsx, err := prepareTestBook4()
+		f, err := prepareTestBook4()
 		if !assert.NoError(t, err) {
 			t.FailNow()
 		}
-		xlsx.DeleteSheet("Sheet1")
-		xlsx.AddComment("Sheet1", "A1", "")
-		xlsx.AddComment("Sheet1", "A1", `{"author":"Excelize: ","text":"This is a comment."}`)
-		assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestSetDeleteSheet.TestBook4.xlsx")))
+		f.DeleteSheet("Sheet1")
+		f.AddComment("Sheet1", "A1", "")
+		f.AddComment("Sheet1", "A1", `{"author":"Excelize: ","text":"This is a comment."}`)
+		assert.NoError(t, f.SaveAs(filepath.Join("test", "TestSetDeleteSheet.TestBook4.xlsx")))
 	})
 }
 
 func TestSheetVisibility(t *testing.T) {
-	xlsx, err := prepareTestBook1()
+	f, err := prepareTestBook1()
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	xlsx.SetSheetVisible("Sheet2", false)
-	xlsx.SetSheetVisible("Sheet1", false)
-	xlsx.SetSheetVisible("Sheet1", true)
-	xlsx.GetSheetVisible("Sheet1")
+	f.SetSheetVisible("Sheet2", false)
+	f.SetSheetVisible("Sheet1", false)
+	f.SetSheetVisible("Sheet1", true)
+	f.GetSheetVisible("Sheet1")
 
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestSheetVisibility.xlsx")))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestSheetVisibility.xlsx")))
 }
 
 func TestColumnVisibility(t *testing.T) {
 	t.Run("TestBook1", func(t *testing.T) {
-		xlsx, err := prepareTestBook1()
+		f, err := prepareTestBook1()
 		if !assert.NoError(t, err) {
 			t.FailNow()
 		}
 
-		assert.NoError(t, xlsx.SetColVisible("Sheet1", "F", false))
-		assert.NoError(t, xlsx.SetColVisible("Sheet1", "F", true))
-		visible, err := xlsx.GetColVisible("Sheet1", "F")
+		assert.NoError(t, f.SetColVisible("Sheet1", "F", false))
+		assert.NoError(t, f.SetColVisible("Sheet1", "F", true))
+		visible, err := f.GetColVisible("Sheet1", "F")
 		assert.Equal(t, true, visible)
 		assert.NoError(t, err)
 
 		// Test get column visiable on not exists worksheet.
-		_, err = xlsx.GetColVisible("SheetN", "F")
+		_, err = f.GetColVisible("SheetN", "F")
 		assert.EqualError(t, err, "sheet SheetN is not exist")
 
 		// Test get column visiable with illegal cell coordinates.
-		_, err = xlsx.GetColVisible("Sheet1", "*")
+		_, err = f.GetColVisible("Sheet1", "*")
 		assert.EqualError(t, err, `invalid column name "*"`)
-		assert.EqualError(t, xlsx.SetColVisible("Sheet1", "*", false), `invalid column name "*"`)
+		assert.EqualError(t, f.SetColVisible("Sheet1", "*", false), `invalid column name "*"`)
 
-		xlsx.NewSheet("Sheet3")
-		assert.NoError(t, xlsx.SetColVisible("Sheet3", "E", false))
+		f.NewSheet("Sheet3")
+		assert.NoError(t, f.SetColVisible("Sheet3", "E", false))
 
-		assert.EqualError(t, xlsx.SetColVisible("SheetN", "E", false), "sheet SheetN is not exist")
-		assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestColumnVisibility.xlsx")))
+		assert.EqualError(t, f.SetColVisible("SheetN", "E", false), "sheet SheetN is not exist")
+		assert.NoError(t, f.SaveAs(filepath.Join("test", "TestColumnVisibility.xlsx")))
 	})
 
 	t.Run("TestBook3", func(t *testing.T) {
-		xlsx, err := prepareTestBook3()
+		f, err := prepareTestBook3()
 		if !assert.NoError(t, err) {
 			t.FailNow()
 		}
-		xlsx.GetColVisible("Sheet1", "B")
+		f.GetColVisible("Sheet1", "B")
 	})
 }
 
 func TestCopySheet(t *testing.T) {
-	xlsx, err := prepareTestBook1()
+	f, err := prepareTestBook1()
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	idx := xlsx.NewSheet("CopySheet")
-	assert.EqualError(t, xlsx.CopySheet(1, idx), "sheet sheet1 is not exist")
+	idx := f.NewSheet("CopySheet")
+	assert.EqualError(t, f.CopySheet(1, idx), "sheet sheet1 is not exist")
 
-	xlsx.SetCellValue("Sheet4", "F1", "Hello")
-	val, err := xlsx.GetCellValue("Sheet1", "F1")
+	f.SetCellValue("Sheet4", "F1", "Hello")
+	val, err := f.GetCellValue("Sheet1", "F1")
 	assert.NoError(t, err)
 	assert.NotEqual(t, "Hello", val)
 
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestCopySheet.xlsx")))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestCopySheet.xlsx")))
 }
 
 func TestCopySheetError(t *testing.T) {
-	xlsx, err := prepareTestBook1()
+	f, err := prepareTestBook1()
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	err = xlsx.CopySheet(0, -1)
+	err = f.CopySheet(0, -1)
 	if !assert.EqualError(t, err, "invalid worksheet index") {
 		t.FailNow()
 	}
 
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestCopySheetError.xlsx")))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestCopySheetError.xlsx")))
 }
 
 func TestAddTable(t *testing.T) {
-	xlsx, err := prepareTestBook1()
+	f, err := prepareTestBook1()
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	err = xlsx.AddTable("Sheet1", "B26", "A21", `{}`)
+	err = f.AddTable("Sheet1", "B26", "A21", `{}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	err = xlsx.AddTable("Sheet2", "A2", "B5", `{"table_name":"table","table_style":"TableStyleMedium2", "show_first_column":true,"show_last_column":true,"show_row_stripes":false,"show_column_stripes":true}`)
+	err = f.AddTable("Sheet2", "A2", "B5", `{"table_name":"table","table_style":"TableStyleMedium2", "show_first_column":true,"show_last_column":true,"show_row_stripes":false,"show_column_stripes":true}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	err = xlsx.AddTable("Sheet2", "F1", "F1", `{"table_style":"TableStyleMedium8"}`)
+	err = f.AddTable("Sheet2", "F1", "F1", `{"table_style":"TableStyleMedium8"}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
 	// Test add table with illegal formatset.
-	assert.EqualError(t, xlsx.AddTable("Sheet1", "B26", "A21", `{x}`), "invalid character 'x' looking for beginning of object key string")
+	assert.EqualError(t, f.AddTable("Sheet1", "B26", "A21", `{x}`), "invalid character 'x' looking for beginning of object key string")
 	// Test add table with illegal cell coordinates.
-	assert.EqualError(t, xlsx.AddTable("Sheet1", "A", "B1", `{}`), `cannot convert cell "A" to coordinates: invalid cell name "A"`)
-	assert.EqualError(t, xlsx.AddTable("Sheet1", "A1", "B", `{}`), `cannot convert cell "B" to coordinates: invalid cell name "B"`)
+	assert.EqualError(t, f.AddTable("Sheet1", "A", "B1", `{}`), `cannot convert cell "A" to coordinates: invalid cell name "A"`)
+	assert.EqualError(t, f.AddTable("Sheet1", "A1", "B", `{}`), `cannot convert cell "B" to coordinates: invalid cell name "B"`)
 
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestAddTable.xlsx")))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestAddTable.xlsx")))
 
 	// Test addTable with illegal cell coordinates.
-	f := NewFile()
+	f = NewFile()
 	assert.EqualError(t, f.addTable("sheet1", "", 0, 0, 0, 0, 0, nil), "invalid cell coordinates [0, 0]")
 	assert.EqualError(t, f.addTable("sheet1", "", 1, 1, 0, 0, 0, nil), "invalid cell coordinates [0, 0]")
 }
 
 func TestAddShape(t *testing.T) {
-	xlsx, err := prepareTestBook1()
+	f, err := prepareTestBook1()
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	xlsx.AddShape("Sheet1", "A30", `{"type":"rect","paragraph":[{"text":"Rectangle","font":{"color":"CD5C5C"}},{"text":"Shape","font":{"bold":true,"color":"2980B9"}}]}`)
-	xlsx.AddShape("Sheet1", "B30", `{"type":"rect","paragraph":[{"text":"Rectangle"},{}]}`)
-	xlsx.AddShape("Sheet1", "C30", `{"type":"rect","paragraph":[]}`)
-	xlsx.AddShape("Sheet3", "H1", `{"type":"ellipseRibbon", "color":{"line":"#4286f4","fill":"#8eb9ff"}, "paragraph":[{"font":{"bold":true,"italic":true,"family":"Berlin Sans FB Demi","size":36,"color":"#777777","underline":"single"}}], "height": 90}`)
-	xlsx.AddShape("Sheet3", "H1", "")
+	f.AddShape("Sheet1", "A30", `{"type":"rect","paragraph":[{"text":"Rectangle","font":{"color":"CD5C5C"}},{"text":"Shape","font":{"bold":true,"color":"2980B9"}}]}`)
+	f.AddShape("Sheet1", "B30", `{"type":"rect","paragraph":[{"text":"Rectangle"},{}]}`)
+	f.AddShape("Sheet1", "C30", `{"type":"rect","paragraph":[]}`)
+	f.AddShape("Sheet3", "H1", `{"type":"ellipseRibbon", "color":{"line":"#4286f4","fill":"#8eb9ff"}, "paragraph":[{"font":{"bold":true,"italic":true,"family":"Berlin Sans FB Demi","size":36,"color":"#777777","underline":"single"}}], "height": 90}`)
+	f.AddShape("Sheet3", "H1", "")
 
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestAddShape.xlsx")))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestAddShape.xlsx")))
 }
 
 func TestAddComments(t *testing.T) {
-	xlsx, err := prepareTestBook1()
+	f, err := prepareTestBook1()
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
 	s := strings.Repeat("c", 32768)
-	xlsx.AddComment("Sheet1", "A30", `{"author":"`+s+`","text":"`+s+`"}`)
-	xlsx.AddComment("Sheet2", "B7", `{"author":"Excelize: ","text":"This is a comment."}`)
+	f.AddComment("Sheet1", "A30", `{"author":"`+s+`","text":"`+s+`"}`)
+	f.AddComment("Sheet2", "B7", `{"author":"Excelize: ","text":"This is a comment."}`)
 
-	if assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestAddComments.xlsx"))) {
-		assert.Len(t, xlsx.GetComments(), 2)
+	if assert.NoError(t, f.SaveAs(filepath.Join("test", "TestAddComments.xlsx"))) {
+		assert.Len(t, f.GetComments(), 2)
 	}
 }
 
@@ -924,7 +932,7 @@ func TestGetSheetComments(t *testing.T) {
 func TestAutoFilter(t *testing.T) {
 	outFile := filepath.Join("test", "TestAutoFilter%d.xlsx")
 
-	xlsx, err := prepareTestBook1()
+	f, err := prepareTestBook1()
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
@@ -942,21 +950,21 @@ func TestAutoFilter(t *testing.T) {
 
 	for i, format := range formats {
 		t.Run(fmt.Sprintf("Expression%d", i+1), func(t *testing.T) {
-			err = xlsx.AutoFilter("Sheet1", "D4", "B1", format)
+			err = f.AutoFilter("Sheet1", "D4", "B1", format)
 			assert.NoError(t, err)
-			assert.NoError(t, xlsx.SaveAs(fmt.Sprintf(outFile, i+1)))
+			assert.NoError(t, f.SaveAs(fmt.Sprintf(outFile, i+1)))
 		})
 	}
 
 	// testing AutoFilter with illegal cell coordinates.
-	assert.EqualError(t, xlsx.AutoFilter("Sheet1", "A", "B1", ""), `cannot convert cell "A" to coordinates: invalid cell name "A"`)
-	assert.EqualError(t, xlsx.AutoFilter("Sheet1", "A1", "B", ""), `cannot convert cell "B" to coordinates: invalid cell name "B"`)
+	assert.EqualError(t, f.AutoFilter("Sheet1", "A", "B1", ""), `cannot convert cell "A" to coordinates: invalid cell name "A"`)
+	assert.EqualError(t, f.AutoFilter("Sheet1", "A1", "B", ""), `cannot convert cell "B" to coordinates: invalid cell name "B"`)
 }
 
 func TestAutoFilterError(t *testing.T) {
 	outFile := filepath.Join("test", "TestAutoFilterError%d.xlsx")
 
-	xlsx, err := prepareTestBook1()
+	f, err := prepareTestBook1()
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
@@ -971,16 +979,16 @@ func TestAutoFilterError(t *testing.T) {
 	}
 	for i, format := range formats {
 		t.Run(fmt.Sprintf("Expression%d", i+1), func(t *testing.T) {
-			err = xlsx.AutoFilter("Sheet3", "D4", "B1", format)
+			err = f.AutoFilter("Sheet3", "D4", "B1", format)
 			if assert.Error(t, err) {
-				assert.NoError(t, xlsx.SaveAs(fmt.Sprintf(outFile, i+1)))
+				assert.NoError(t, f.SaveAs(fmt.Sprintf(outFile, i+1)))
 			}
 		})
 	}
 }
 
 func TestAddChart(t *testing.T) {
-	xlsx, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
+	f, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
@@ -988,258 +996,258 @@ func TestAddChart(t *testing.T) {
 	categories := map[string]string{"A30": "Small", "A31": "Normal", "A32": "Large", "B29": "Apple", "C29": "Orange", "D29": "Pear"}
 	values := map[string]int{"B30": 2, "C30": 3, "D30": 3, "B31": 5, "C31": 2, "D31": 4, "B32": 6, "C32": 7, "D32": 8}
 	for k, v := range categories {
-		assert.NoError(t, xlsx.SetCellValue("Sheet1", k, v))
+		assert.NoError(t, f.SetCellValue("Sheet1", k, v))
 	}
 	for k, v := range values {
-		assert.NoError(t, xlsx.SetCellValue("Sheet1", k, v))
+		assert.NoError(t, f.SetCellValue("Sheet1", k, v))
 	}
-	assert.EqualError(t, xlsx.AddChart("Sheet1", "P1", ""), "unexpected end of JSON input")
+	assert.EqualError(t, f.AddChart("Sheet1", "P1", ""), "unexpected end of JSON input")
 
 	// Test add chart on not exists worksheet.
-	assert.EqualError(t, xlsx.AddChart("SheetN", "P1", "{}"), "sheet SheetN is not exist")
+	assert.EqualError(t, f.AddChart("SheetN", "P1", "{}"), "sheet SheetN is not exist")
 
-	assert.NoError(t, xlsx.AddChart("Sheet1", "P1", `{"type":"col","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 2D Column Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
-	assert.NoError(t, xlsx.AddChart("Sheet1", "X1", `{"type":"colStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 2D Stacked Column Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
-	assert.NoError(t, xlsx.AddChart("Sheet1", "P16", `{"type":"colPercentStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 100% Stacked Column Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
-	assert.NoError(t, xlsx.AddChart("Sheet1", "X16", `{"type":"col3DClustered","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"bottom","show_legend_key":false},"title":{"name":"Fruit 3D Clustered Column Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
-	assert.NoError(t, xlsx.AddChart("Sheet1", "P30", `{"type":"col3DStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 3D 100% Stacked Bar Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
-	assert.NoError(t, xlsx.AddChart("Sheet1", "X30", `{"type":"col3DPercentStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 3D 100% Stacked Column Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
-	assert.NoError(t, xlsx.AddChart("Sheet1", "P45", `{"type":"col3D","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 3D Column Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
-	assert.NoError(t, xlsx.AddChart("Sheet2", "P1", `{"type":"radar","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"top_right","show_legend_key":false},"title":{"name":"Fruit Radar Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"span"}`))
-	assert.NoError(t, xlsx.AddChart("Sheet2", "X1", `{"type":"scatter","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"bottom","show_legend_key":false},"title":{"name":"Fruit Scatter Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
-	assert.NoError(t, xlsx.AddChart("Sheet2", "P16", `{"type":"doughnut","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"right","show_legend_key":false},"title":{"name":"Fruit Doughnut Chart"},"plotarea":{"show_bubble_size":false,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":false,"show_val":false},"show_blanks_as":"zero"}`))
-	assert.NoError(t, xlsx.AddChart("Sheet2", "X16", `{"type":"line","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"top","show_legend_key":false},"title":{"name":"Fruit Line Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
-	assert.NoError(t, xlsx.AddChart("Sheet2", "P32", `{"type":"pie3D","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"bottom","show_legend_key":false},"title":{"name":"Fruit 3D Pie Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":false,"show_val":false},"show_blanks_as":"zero"}`))
-	assert.NoError(t, xlsx.AddChart("Sheet2", "X32", `{"type":"pie","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"bottom","show_legend_key":false},"title":{"name":"Fruit Pie Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":false,"show_val":false},"show_blanks_as":"gap"}`))
-	assert.NoError(t, xlsx.AddChart("Sheet2", "P48", `{"type":"bar","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 2D Clustered Bar Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
-	assert.NoError(t, xlsx.AddChart("Sheet2", "X48", `{"type":"barStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 2D Stacked Bar Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
-	assert.NoError(t, xlsx.AddChart("Sheet2", "P64", `{"type":"barPercentStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 2D Stacked 100% Bar Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
-	assert.NoError(t, xlsx.AddChart("Sheet2", "X64", `{"type":"bar3DClustered","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 3D Clustered Bar Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
-	assert.NoError(t, xlsx.AddChart("Sheet2", "P80", `{"type":"bar3DStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 3D Stacked Bar Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero","y_axis":{"maximum":7.5,"minimum":0.5}}`))
-	assert.NoError(t, xlsx.AddChart("Sheet2", "X80", `{"type":"bar3DPercentStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 3D 100% Stacked Bar Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero","x_axis":{"reverse_order":true,"maximum":0,"minimum":0},"y_axis":{"reverse_order":true,"maximum":0,"minimum":0}}`))
+	assert.NoError(t, f.AddChart("Sheet1", "P1", `{"type":"col","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 2D Column Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
+	assert.NoError(t, f.AddChart("Sheet1", "X1", `{"type":"colStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 2D Stacked Column Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
+	assert.NoError(t, f.AddChart("Sheet1", "P16", `{"type":"colPercentStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 100% Stacked Column Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
+	assert.NoError(t, f.AddChart("Sheet1", "X16", `{"type":"col3DClustered","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"bottom","show_legend_key":false},"title":{"name":"Fruit 3D Clustered Column Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
+	assert.NoError(t, f.AddChart("Sheet1", "P30", `{"type":"col3DStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 3D 100% Stacked Bar Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
+	assert.NoError(t, f.AddChart("Sheet1", "X30", `{"type":"col3DPercentStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 3D 100% Stacked Column Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
+	assert.NoError(t, f.AddChart("Sheet1", "P45", `{"type":"col3D","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 3D Column Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
+	assert.NoError(t, f.AddChart("Sheet2", "P1", `{"type":"radar","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"top_right","show_legend_key":false},"title":{"name":"Fruit Radar Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"span"}`))
+	assert.NoError(t, f.AddChart("Sheet2", "X1", `{"type":"scatter","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"bottom","show_legend_key":false},"title":{"name":"Fruit Scatter Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
+	assert.NoError(t, f.AddChart("Sheet2", "P16", `{"type":"doughnut","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"right","show_legend_key":false},"title":{"name":"Fruit Doughnut Chart"},"plotarea":{"show_bubble_size":false,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":false,"show_val":false},"show_blanks_as":"zero"}`))
+	assert.NoError(t, f.AddChart("Sheet2", "X16", `{"type":"line","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"top","show_legend_key":false},"title":{"name":"Fruit Line Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
+	assert.NoError(t, f.AddChart("Sheet2", "P32", `{"type":"pie3D","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"bottom","show_legend_key":false},"title":{"name":"Fruit 3D Pie Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":false,"show_val":false},"show_blanks_as":"zero"}`))
+	assert.NoError(t, f.AddChart("Sheet2", "X32", `{"type":"pie","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"bottom","show_legend_key":false},"title":{"name":"Fruit Pie Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":false,"show_val":false},"show_blanks_as":"gap"}`))
+	assert.NoError(t, f.AddChart("Sheet2", "P48", `{"type":"bar","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 2D Clustered Bar Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
+	assert.NoError(t, f.AddChart("Sheet2", "X48", `{"type":"barStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 2D Stacked Bar Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
+	assert.NoError(t, f.AddChart("Sheet2", "P64", `{"type":"barPercentStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 2D Stacked 100% Bar Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
+	assert.NoError(t, f.AddChart("Sheet2", "X64", `{"type":"bar3DClustered","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 3D Clustered Bar Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
+	assert.NoError(t, f.AddChart("Sheet2", "P80", `{"type":"bar3DStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 3D Stacked Bar Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero","y_axis":{"maximum":7.5,"minimum":0.5}}`))
+	assert.NoError(t, f.AddChart("Sheet2", "X80", `{"type":"bar3DPercentStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 3D 100% Stacked Bar Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero","x_axis":{"reverse_order":true,"maximum":0,"minimum":0},"y_axis":{"reverse_order":true,"maximum":0,"minimum":0}}`))
 	// area series charts
-	assert.NoError(t, xlsx.AddChart("Sheet2", "AF1", `{"type":"area","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 2D Area Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
-	assert.NoError(t, xlsx.AddChart("Sheet2", "AN1", `{"type":"areaStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 2D Stacked Area Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
-	assert.NoError(t, xlsx.AddChart("Sheet2", "AF16", `{"type":"areaPercentStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 2D 100% Stacked Area Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
-	assert.NoError(t, xlsx.AddChart("Sheet2", "AN16", `{"type":"area3D","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 3D Area Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
-	assert.NoError(t, xlsx.AddChart("Sheet2", "AF32", `{"type":"area3DStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 3D Stacked Area Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
-	assert.NoError(t, xlsx.AddChart("Sheet2", "AN32", `{"type":"area3DPercentStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 3D 100% Stacked Area Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
+	assert.NoError(t, f.AddChart("Sheet2", "AF1", `{"type":"area","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 2D Area Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
+	assert.NoError(t, f.AddChart("Sheet2", "AN1", `{"type":"areaStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 2D Stacked Area Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
+	assert.NoError(t, f.AddChart("Sheet2", "AF16", `{"type":"areaPercentStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 2D 100% Stacked Area Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
+	assert.NoError(t, f.AddChart("Sheet2", "AN16", `{"type":"area3D","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 3D Area Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
+	assert.NoError(t, f.AddChart("Sheet2", "AF32", `{"type":"area3DStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 3D Stacked Area Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
+	assert.NoError(t, f.AddChart("Sheet2", "AN32", `{"type":"area3DPercentStacked","series":[{"name":"Sheet1!$A$30","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$30:$D$30"},{"name":"Sheet1!$A$31","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$31:$D$31"},{"name":"Sheet1!$A$32","categories":"Sheet1!$B$29:$D$29","values":"Sheet1!$B$32:$D$32"}],"format":{"x_scale":1.0,"y_scale":1.0,"x_offset":15,"y_offset":10,"print_obj":true,"lock_aspect_ratio":false,"locked":false},"legend":{"position":"left","show_legend_key":false},"title":{"name":"Fruit 3D 100% Stacked Area Chart"},"plotarea":{"show_bubble_size":true,"show_cat_name":false,"show_leader_lines":false,"show_percent":true,"show_series_name":true,"show_val":true},"show_blanks_as":"zero"}`))
 
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestAddChart.xlsx")))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestAddChart.xlsx")))
 }
 
 func TestInsertCol(t *testing.T) {
-	xlsx := NewFile()
-	sheet1 := xlsx.GetSheetName(1)
+	f := NewFile()
+	sheet1 := f.GetSheetName(1)
 
-	fillCells(xlsx, sheet1, 10, 10)
+	fillCells(f, sheet1, 10, 10)
 
-	xlsx.SetCellHyperLink(sheet1, "A5", "https://github.com/360EntSecGroup-Skylar/excelize", "External")
-	xlsx.MergeCell(sheet1, "A1", "C3")
+	f.SetCellHyperLink(sheet1, "A5", "https://github.com/360EntSecGroup-Skylar/excelize", "External")
+	f.MergeCell(sheet1, "A1", "C3")
 
-	err := xlsx.AutoFilter(sheet1, "A2", "B2", `{"column":"B","expression":"x != blanks"}`)
+	err := f.AutoFilter(sheet1, "A2", "B2", `{"column":"B","expression":"x != blanks"}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	assert.NoError(t, xlsx.InsertCol(sheet1, "A"))
+	assert.NoError(t, f.InsertCol(sheet1, "A"))
 
 	// Test insert column with illegal cell coordinates.
-	assert.EqualError(t, xlsx.InsertCol("Sheet1", "*"), `invalid column name "*"`)
+	assert.EqualError(t, f.InsertCol("Sheet1", "*"), `invalid column name "*"`)
 
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestInsertCol.xlsx")))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestInsertCol.xlsx")))
 }
 
 func TestRemoveCol(t *testing.T) {
-	xlsx := NewFile()
-	sheet1 := xlsx.GetSheetName(1)
+	f := NewFile()
+	sheet1 := f.GetSheetName(1)
 
-	fillCells(xlsx, sheet1, 10, 15)
+	fillCells(f, sheet1, 10, 15)
 
-	xlsx.SetCellHyperLink(sheet1, "A5", "https://github.com/360EntSecGroup-Skylar/excelize", "External")
-	xlsx.SetCellHyperLink(sheet1, "C5", "https://github.com", "External")
+	f.SetCellHyperLink(sheet1, "A5", "https://github.com/360EntSecGroup-Skylar/excelize", "External")
+	f.SetCellHyperLink(sheet1, "C5", "https://github.com", "External")
 
-	xlsx.MergeCell(sheet1, "A1", "B1")
-	xlsx.MergeCell(sheet1, "A2", "B2")
+	f.MergeCell(sheet1, "A1", "B1")
+	f.MergeCell(sheet1, "A2", "B2")
 
-	assert.NoError(t, xlsx.RemoveCol(sheet1, "A"))
-	assert.NoError(t, xlsx.RemoveCol(sheet1, "A"))
+	assert.NoError(t, f.RemoveCol(sheet1, "A"))
+	assert.NoError(t, f.RemoveCol(sheet1, "A"))
 
 	// Test remove column with illegal cell coordinates.
-	assert.EqualError(t, xlsx.RemoveCol("Sheet1", "*"), `invalid column name "*"`)
+	assert.EqualError(t, f.RemoveCol("Sheet1", "*"), `invalid column name "*"`)
 
 	// Test remove column on not exists worksheet.
-	assert.EqualError(t, xlsx.RemoveCol("SheetN", "B"), "sheet SheetN is not exist")
+	assert.EqualError(t, f.RemoveCol("SheetN", "B"), "sheet SheetN is not exist")
 
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestRemoveCol.xlsx")))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestRemoveCol.xlsx")))
 }
 
 func TestSetPane(t *testing.T) {
-	xlsx := NewFile()
-	xlsx.SetPanes("Sheet1", `{"freeze":false,"split":false}`)
-	xlsx.NewSheet("Panes 2")
-	xlsx.SetPanes("Panes 2", `{"freeze":true,"split":false,"x_split":1,"y_split":0,"top_left_cell":"B1","active_pane":"topRight","panes":[{"sqref":"K16","active_cell":"K16","pane":"topRight"}]}`)
-	xlsx.NewSheet("Panes 3")
-	xlsx.SetPanes("Panes 3", `{"freeze":false,"split":true,"x_split":3270,"y_split":1800,"top_left_cell":"N57","active_pane":"bottomLeft","panes":[{"sqref":"I36","active_cell":"I36"},{"sqref":"G33","active_cell":"G33","pane":"topRight"},{"sqref":"J60","active_cell":"J60","pane":"bottomLeft"},{"sqref":"O60","active_cell":"O60","pane":"bottomRight"}]}`)
-	xlsx.NewSheet("Panes 4")
-	xlsx.SetPanes("Panes 4", `{"freeze":true,"split":false,"x_split":0,"y_split":9,"top_left_cell":"A34","active_pane":"bottomLeft","panes":[{"sqref":"A11:XFD11","active_cell":"A11","pane":"bottomLeft"}]}`)
-	xlsx.SetPanes("Panes 4", "")
+	f := NewFile()
+	f.SetPanes("Sheet1", `{"freeze":false,"split":false}`)
+	f.NewSheet("Panes 2")
+	f.SetPanes("Panes 2", `{"freeze":true,"split":false,"x_split":1,"y_split":0,"top_left_cell":"B1","active_pane":"topRight","panes":[{"sqref":"K16","active_cell":"K16","pane":"topRight"}]}`)
+	f.NewSheet("Panes 3")
+	f.SetPanes("Panes 3", `{"freeze":false,"split":true,"x_split":3270,"y_split":1800,"top_left_cell":"N57","active_pane":"bottomLeft","panes":[{"sqref":"I36","active_cell":"I36"},{"sqref":"G33","active_cell":"G33","pane":"topRight"},{"sqref":"J60","active_cell":"J60","pane":"bottomLeft"},{"sqref":"O60","active_cell":"O60","pane":"bottomRight"}]}`)
+	f.NewSheet("Panes 4")
+	f.SetPanes("Panes 4", `{"freeze":true,"split":false,"x_split":0,"y_split":9,"top_left_cell":"A34","active_pane":"bottomLeft","panes":[{"sqref":"A11:XFD11","active_cell":"A11","pane":"bottomLeft"}]}`)
+	f.SetPanes("Panes 4", "")
 
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestSetPane.xlsx")))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestSetPane.xlsx")))
 }
 
 func TestConditionalFormat(t *testing.T) {
-	xlsx := NewFile()
-	sheet1 := xlsx.GetSheetName(1)
+	f := NewFile()
+	sheet1 := f.GetSheetName(1)
 
-	fillCells(xlsx, sheet1, 10, 15)
+	fillCells(f, sheet1, 10, 15)
 
 	var format1, format2, format3 int
 	var err error
 	// Rose format for bad conditional.
-	format1, err = xlsx.NewConditionalStyle(`{"font":{"color":"#9A0511"},"fill":{"type":"pattern","color":["#FEC7CE"],"pattern":1}}`)
+	format1, err = f.NewConditionalStyle(`{"font":{"color":"#9A0511"},"fill":{"type":"pattern","color":["#FEC7CE"],"pattern":1}}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
 	// Light yellow format for neutral conditional.
-	format2, err = xlsx.NewConditionalStyle(`{"fill":{"type":"pattern","color":["#FEEAA0"],"pattern":1}}`)
+	format2, err = f.NewConditionalStyle(`{"fill":{"type":"pattern","color":["#FEEAA0"],"pattern":1}}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
 	// Light green format for good conditional.
-	format3, err = xlsx.NewConditionalStyle(`{"font":{"color":"#09600B"},"fill":{"type":"pattern","color":["#C7EECF"],"pattern":1}}`)
+	format3, err = f.NewConditionalStyle(`{"font":{"color":"#09600B"},"fill":{"type":"pattern","color":["#C7EECF"],"pattern":1}}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
 	// Color scales: 2 color.
-	xlsx.SetConditionalFormat(sheet1, "A1:A10", `[{"type":"2_color_scale","criteria":"=","min_type":"min","max_type":"max","min_color":"#F8696B","max_color":"#63BE7B"}]`)
+	f.SetConditionalFormat(sheet1, "A1:A10", `[{"type":"2_color_scale","criteria":"=","min_type":"min","max_type":"max","min_color":"#F8696B","max_color":"#63BE7B"}]`)
 	// Color scales: 3 color.
-	xlsx.SetConditionalFormat(sheet1, "B1:B10", `[{"type":"3_color_scale","criteria":"=","min_type":"min","mid_type":"percentile","max_type":"max","min_color":"#F8696B","mid_color":"#FFEB84","max_color":"#63BE7B"}]`)
+	f.SetConditionalFormat(sheet1, "B1:B10", `[{"type":"3_color_scale","criteria":"=","min_type":"min","mid_type":"percentile","max_type":"max","min_color":"#F8696B","mid_color":"#FFEB84","max_color":"#63BE7B"}]`)
 	// Hightlight cells rules: between...
-	xlsx.SetConditionalFormat(sheet1, "C1:C10", fmt.Sprintf(`[{"type":"cell","criteria":"between","format":%d,"minimum":"6","maximum":"8"}]`, format1))
+	f.SetConditionalFormat(sheet1, "C1:C10", fmt.Sprintf(`[{"type":"cell","criteria":"between","format":%d,"minimum":"6","maximum":"8"}]`, format1))
 	// Hightlight cells rules: Greater Than...
-	xlsx.SetConditionalFormat(sheet1, "D1:D10", fmt.Sprintf(`[{"type":"cell","criteria":">","format":%d,"value":"6"}]`, format3))
+	f.SetConditionalFormat(sheet1, "D1:D10", fmt.Sprintf(`[{"type":"cell","criteria":">","format":%d,"value":"6"}]`, format3))
 	// Hightlight cells rules: Equal To...
-	xlsx.SetConditionalFormat(sheet1, "E1:E10", fmt.Sprintf(`[{"type":"top","criteria":"=","format":%d}]`, format3))
+	f.SetConditionalFormat(sheet1, "E1:E10", fmt.Sprintf(`[{"type":"top","criteria":"=","format":%d}]`, format3))
 	// Hightlight cells rules: Not Equal To...
-	xlsx.SetConditionalFormat(sheet1, "F1:F10", fmt.Sprintf(`[{"type":"unique","criteria":"=","format":%d}]`, format2))
+	f.SetConditionalFormat(sheet1, "F1:F10", fmt.Sprintf(`[{"type":"unique","criteria":"=","format":%d}]`, format2))
 	// Hightlight cells rules: Duplicate Values...
-	xlsx.SetConditionalFormat(sheet1, "G1:G10", fmt.Sprintf(`[{"type":"duplicate","criteria":"=","format":%d}]`, format2))
+	f.SetConditionalFormat(sheet1, "G1:G10", fmt.Sprintf(`[{"type":"duplicate","criteria":"=","format":%d}]`, format2))
 	// Top/Bottom rules: Top 10%.
-	xlsx.SetConditionalFormat(sheet1, "H1:H10", fmt.Sprintf(`[{"type":"top","criteria":"=","format":%d,"value":"6","percent":true}]`, format1))
+	f.SetConditionalFormat(sheet1, "H1:H10", fmt.Sprintf(`[{"type":"top","criteria":"=","format":%d,"value":"6","percent":true}]`, format1))
 	// Top/Bottom rules: Above Average...
-	xlsx.SetConditionalFormat(sheet1, "I1:I10", fmt.Sprintf(`[{"type":"average","criteria":"=","format":%d, "above_average": true}]`, format3))
+	f.SetConditionalFormat(sheet1, "I1:I10", fmt.Sprintf(`[{"type":"average","criteria":"=","format":%d, "above_average": true}]`, format3))
 	// Top/Bottom rules: Below Average...
-	xlsx.SetConditionalFormat(sheet1, "J1:J10", fmt.Sprintf(`[{"type":"average","criteria":"=","format":%d, "above_average": false}]`, format1))
+	f.SetConditionalFormat(sheet1, "J1:J10", fmt.Sprintf(`[{"type":"average","criteria":"=","format":%d, "above_average": false}]`, format1))
 	// Data Bars: Gradient Fill.
-	xlsx.SetConditionalFormat(sheet1, "K1:K10", `[{"type":"data_bar", "criteria":"=", "min_type":"min","max_type":"max","bar_color":"#638EC6"}]`)
+	f.SetConditionalFormat(sheet1, "K1:K10", `[{"type":"data_bar", "criteria":"=", "min_type":"min","max_type":"max","bar_color":"#638EC6"}]`)
 	// Use a formula to determine which cells to format.
-	xlsx.SetConditionalFormat(sheet1, "L1:L10", fmt.Sprintf(`[{"type":"formula", "criteria":"L2<3", "format":%d}]`, format1))
+	f.SetConditionalFormat(sheet1, "L1:L10", fmt.Sprintf(`[{"type":"formula", "criteria":"L2<3", "format":%d}]`, format1))
 	// Test set invalid format set in conditional format
-	xlsx.SetConditionalFormat(sheet1, "L1:L10", "")
+	f.SetConditionalFormat(sheet1, "L1:L10", "")
 
-	err = xlsx.SaveAs(filepath.Join("test", "TestConditionalFormat.xlsx"))
+	err = f.SaveAs(filepath.Join("test", "TestConditionalFormat.xlsx"))
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
 	// Set conditional format with illegal valid type.
-	xlsx.SetConditionalFormat(sheet1, "K1:K10", `[{"type":"", "criteria":"=", "min_type":"min","max_type":"max","bar_color":"#638EC6"}]`)
+	f.SetConditionalFormat(sheet1, "K1:K10", `[{"type":"", "criteria":"=", "min_type":"min","max_type":"max","bar_color":"#638EC6"}]`)
 	// Set conditional format with illegal criteria type.
-	xlsx.SetConditionalFormat(sheet1, "K1:K10", `[{"type":"data_bar", "criteria":"", "min_type":"min","max_type":"max","bar_color":"#638EC6"}]`)
+	f.SetConditionalFormat(sheet1, "K1:K10", `[{"type":"data_bar", "criteria":"", "min_type":"min","max_type":"max","bar_color":"#638EC6"}]`)
 
 	// Set conditional format with file without dxfs element shold not return error.
-	xlsx, err = OpenFile(filepath.Join("test", "Book1.xlsx"))
+	f, err = OpenFile(filepath.Join("test", "Book1.xlsx"))
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	_, err = xlsx.NewConditionalStyle(`{"font":{"color":"#9A0511"},"fill":{"type":"pattern","color":["#FEC7CE"],"pattern":1}}`)
+	_, err = f.NewConditionalStyle(`{"font":{"color":"#9A0511"},"fill":{"type":"pattern","color":["#FEC7CE"],"pattern":1}}`)
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 }
 
 func TestConditionalFormatError(t *testing.T) {
-	xlsx := NewFile()
-	sheet1 := xlsx.GetSheetName(1)
+	f := NewFile()
+	sheet1 := f.GetSheetName(1)
 
-	fillCells(xlsx, sheet1, 10, 15)
+	fillCells(f, sheet1, 10, 15)
 
 	// Set conditional format with illegal JSON string should return error
-	_, err := xlsx.NewConditionalStyle("")
+	_, err := f.NewConditionalStyle("")
 	if !assert.EqualError(t, err, "unexpected end of JSON input") {
 		t.FailNow()
 	}
 }
 
 func TestSharedStrings(t *testing.T) {
-	xlsx, err := OpenFile(filepath.Join("test", "SharedStrings.xlsx"))
+	f, err := OpenFile(filepath.Join("test", "SharedStrings.xlsx"))
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
-	xlsx.GetRows("Sheet1")
+	f.GetRows("Sheet1")
 }
 
 func TestSetSheetRow(t *testing.T) {
-	xlsx, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
+	f, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	xlsx.SetSheetRow("Sheet1", "B27", &[]interface{}{"cell", nil, int32(42), float64(42), time.Now().UTC()})
+	f.SetSheetRow("Sheet1", "B27", &[]interface{}{"cell", nil, int32(42), float64(42), time.Now().UTC()})
 
-	assert.EqualError(t, xlsx.SetSheetRow("Sheet1", "", &[]interface{}{"cell", nil, 2}),
+	assert.EqualError(t, f.SetSheetRow("Sheet1", "", &[]interface{}{"cell", nil, 2}),
 		`cannot convert cell "" to coordinates: invalid cell name ""`)
 
-	assert.EqualError(t, xlsx.SetSheetRow("Sheet1", "B27", []interface{}{}), `pointer to slice expected`)
-	assert.EqualError(t, xlsx.SetSheetRow("Sheet1", "B27", &xlsx), `pointer to slice expected`)
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestSetSheetRow.xlsx")))
+	assert.EqualError(t, f.SetSheetRow("Sheet1", "B27", []interface{}{}), `pointer to slice expected`)
+	assert.EqualError(t, f.SetSheetRow("Sheet1", "B27", &f), `pointer to slice expected`)
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestSetSheetRow.xlsx")))
 }
 
 func TestOutlineLevel(t *testing.T) {
-	xlsx := NewFile()
-	xlsx.NewSheet("Sheet2")
-	xlsx.SetColOutlineLevel("Sheet1", "D", 4)
-	xlsx.GetColOutlineLevel("Sheet1", "D")
-	xlsx.GetColOutlineLevel("Shee2", "A")
-	xlsx.SetColWidth("Sheet2", "A", "D", 13)
-	xlsx.SetColOutlineLevel("Sheet2", "B", 2)
-	xlsx.SetRowOutlineLevel("Sheet1", 2, 250)
+	f := NewFile()
+	f.NewSheet("Sheet2")
+	f.SetColOutlineLevel("Sheet1", "D", 4)
+	f.GetColOutlineLevel("Sheet1", "D")
+	f.GetColOutlineLevel("Shee2", "A")
+	f.SetColWidth("Sheet2", "A", "D", 13)
+	f.SetColOutlineLevel("Sheet2", "B", 2)
+	f.SetRowOutlineLevel("Sheet1", 2, 250)
 
 	// Test set and get column outline level with illegal cell coordinates.
-	assert.EqualError(t, xlsx.SetColOutlineLevel("Sheet1", "*", 1), `invalid column name "*"`)
-	_, err := xlsx.GetColOutlineLevel("Sheet1", "*")
+	assert.EqualError(t, f.SetColOutlineLevel("Sheet1", "*", 1), `invalid column name "*"`)
+	_, err := f.GetColOutlineLevel("Sheet1", "*")
 	assert.EqualError(t, err, `invalid column name "*"`)
 
 	// Test set column outline level on not exists worksheet.
-	assert.EqualError(t, xlsx.SetColOutlineLevel("SheetN", "E", 2), "sheet SheetN is not exist")
+	assert.EqualError(t, f.SetColOutlineLevel("SheetN", "E", 2), "sheet SheetN is not exist")
 
-	assert.EqualError(t, xlsx.SetRowOutlineLevel("Sheet1", 0, 1), "invalid row number 0")
-	level, err := xlsx.GetRowOutlineLevel("Sheet1", 2)
+	assert.EqualError(t, f.SetRowOutlineLevel("Sheet1", 0, 1), "invalid row number 0")
+	level, err := f.GetRowOutlineLevel("Sheet1", 2)
 	assert.NoError(t, err)
 	assert.Equal(t, uint8(250), level)
 
-	_, err = xlsx.GetRowOutlineLevel("Sheet1", 0)
+	_, err = f.GetRowOutlineLevel("Sheet1", 0)
 	assert.EqualError(t, err, `invalid row number 0`)
 
-	level, err = xlsx.GetRowOutlineLevel("Sheet1", 10)
+	level, err = f.GetRowOutlineLevel("Sheet1", 10)
 	assert.NoError(t, err)
 	assert.Equal(t, uint8(0), level)
 
-	err = xlsx.SaveAs(filepath.Join("test", "TestOutlineLevel.xlsx"))
+	err = f.SaveAs(filepath.Join("test", "TestOutlineLevel.xlsx"))
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
-	xlsx, err = OpenFile(filepath.Join("test", "Book1.xlsx"))
+	f, err = OpenFile(filepath.Join("test", "Book1.xlsx"))
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
-	xlsx.SetColOutlineLevel("Sheet2", "B", 2)
+	f.SetColOutlineLevel("Sheet2", "B", 2)
 }
 
 func TestThemeColor(t *testing.T) {
@@ -1268,44 +1276,44 @@ func TestHSL(t *testing.T) {
 }
 
 func TestSearchSheet(t *testing.T) {
-	xlsx, err := OpenFile(filepath.Join("test", "SharedStrings.xlsx"))
+	f, err := OpenFile(filepath.Join("test", "SharedStrings.xlsx"))
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 
 	// Test search in a not exists worksheet.
-	t.Log(xlsx.SearchSheet("Sheet4", ""))
+	t.Log(f.SearchSheet("Sheet4", ""))
 	// Test search a not exists value.
-	t.Log(xlsx.SearchSheet("Sheet1", "X"))
-	t.Log(xlsx.SearchSheet("Sheet1", "A"))
+	t.Log(f.SearchSheet("Sheet1", "X"))
+	t.Log(f.SearchSheet("Sheet1", "A"))
 	// Test search the coordinates where the numerical value in the range of
 	// "0-9" of Sheet1 is described by regular expression:
-	t.Log(xlsx.SearchSheet("Sheet1", "[0-9]", true))
+	t.Log(f.SearchSheet("Sheet1", "[0-9]", true))
 }
 
 func TestProtectSheet(t *testing.T) {
-	xlsx := NewFile()
-	xlsx.ProtectSheet("Sheet1", nil)
-	xlsx.ProtectSheet("Sheet1", &FormatSheetProtection{
+	f := NewFile()
+	f.ProtectSheet("Sheet1", nil)
+	f.ProtectSheet("Sheet1", &FormatSheetProtection{
 		Password:      "password",
 		EditScenarios: false,
 	})
 
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestProtectSheet.xlsx")))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestProtectSheet.xlsx")))
 	// Test protect not exists worksheet.
-	assert.EqualError(t, xlsx.ProtectSheet("SheetN", nil), "sheet SheetN is not exist")
+	assert.EqualError(t, f.ProtectSheet("SheetN", nil), "sheet SheetN is not exist")
 }
 
 func TestUnprotectSheet(t *testing.T) {
-	xlsx, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
+	f, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
 	if !assert.NoError(t, err) {
 		t.FailNow()
 	}
 	// Test unprotect not exists worksheet.
-	assert.EqualError(t, xlsx.UnprotectSheet("SheetN"), "sheet SheetN is not exist")
+	assert.EqualError(t, f.UnprotectSheet("SheetN"), "sheet SheetN is not exist")
 
-	xlsx.UnprotectSheet("Sheet1")
-	assert.NoError(t, xlsx.SaveAs(filepath.Join("test", "TestUnprotectSheet.xlsx")))
+	f.UnprotectSheet("Sheet1")
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestUnprotectSheet.xlsx")))
 }
 
 func TestSetDefaultTimeStyle(t *testing.T) {
@@ -1315,19 +1323,19 @@ func TestSetDefaultTimeStyle(t *testing.T) {
 }
 
 func prepareTestBook1() (*File, error) {
-	xlsx, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
+	f, err := OpenFile(filepath.Join("test", "Book1.xlsx"))
 	if err != nil {
 		return nil, err
 	}
 
-	err = xlsx.AddPicture("Sheet2", "I9", filepath.Join("test", "images", "excel.jpg"),
+	err = f.AddPicture("Sheet2", "I9", filepath.Join("test", "images", "excel.jpg"),
 		`{"x_offset": 140, "y_offset": 120, "hyperlink": "#Sheet2!D8", "hyperlink_type": "Location"}`)
 	if err != nil {
 		return nil, err
 	}
 
 	// Test add picture to worksheet with offset, external hyperlink and positioning.
-	err = xlsx.AddPicture("Sheet1", "F21", filepath.Join("test", "images", "excel.png"),
+	err = f.AddPicture("Sheet1", "F21", filepath.Join("test", "images", "excel.png"),
 		`{"x_offset": 10, "y_offset": 10, "hyperlink": "https://github.com/360EntSecGroup-Skylar/excelize", "hyperlink_type": "External", "positioning": "oneCell"}`)
 	if err != nil {
 		return nil, err
@@ -1338,52 +1346,52 @@ func prepareTestBook1() (*File, error) {
 		return nil, err
 	}
 
-	err = xlsx.AddPictureFromBytes("Sheet1", "Q1", "", "Excel Logo", ".jpg", file)
+	err = f.AddPictureFromBytes("Sheet1", "Q1", "", "Excel Logo", ".jpg", file)
 	if err != nil {
 		return nil, err
 	}
 
-	return xlsx, nil
+	return f, nil
 }
 
 func prepareTestBook3() (*File, error) {
-	xlsx := NewFile()
-	xlsx.NewSheet("Sheet1")
-	xlsx.NewSheet("XLSXSheet2")
-	xlsx.NewSheet("XLSXSheet3")
-	xlsx.SetCellInt("XLSXSheet2", "A23", 56)
-	xlsx.SetCellStr("Sheet1", "B20", "42")
-	xlsx.SetActiveSheet(0)
+	f := NewFile()
+	f.NewSheet("Sheet1")
+	f.NewSheet("XLSXSheet2")
+	f.NewSheet("XLSXSheet3")
+	f.SetCellInt("XLSXSheet2", "A23", 56)
+	f.SetCellStr("Sheet1", "B20", "42")
+	f.SetActiveSheet(0)
 
-	err := xlsx.AddPicture("Sheet1", "H2", filepath.Join("test", "images", "excel.gif"),
+	err := f.AddPicture("Sheet1", "H2", filepath.Join("test", "images", "excel.gif"),
 		`{"x_scale": 0.5, "y_scale": 0.5, "positioning": "absolute"}`)
 	if err != nil {
 		return nil, err
 	}
 
-	err = xlsx.AddPicture("Sheet1", "C2", filepath.Join("test", "images", "excel.png"), "")
+	err = f.AddPicture("Sheet1", "C2", filepath.Join("test", "images", "excel.png"), "")
 	if err != nil {
 		return nil, err
 	}
 
-	return xlsx, nil
+	return f, nil
 }
 
 func prepareTestBook4() (*File, error) {
-	xlsx := NewFile()
-	xlsx.SetColWidth("Sheet1", "B", "A", 12)
-	xlsx.SetColWidth("Sheet1", "A", "B", 12)
-	xlsx.GetColWidth("Sheet1", "A")
-	xlsx.GetColWidth("Sheet1", "C")
+	f := NewFile()
+	f.SetColWidth("Sheet1", "B", "A", 12)
+	f.SetColWidth("Sheet1", "A", "B", 12)
+	f.GetColWidth("Sheet1", "A")
+	f.GetColWidth("Sheet1", "C")
 
-	return xlsx, nil
+	return f, nil
 }
 
-func fillCells(xlsx *File, sheet string, colCount, rowCount int) {
+func fillCells(f *File, sheet string, colCount, rowCount int) {
 	for col := 1; col <= colCount; col++ {
 		for row := 1; row <= rowCount; row++ {
 			cell, _ := CoordinatesToCellName(col, row)
-			xlsx.SetCellStr(sheet, cell, cell)
+			f.SetCellStr(sheet, cell, cell)
 		}
 	}
 }
diff --git a/shape.go b/shape.go
index f404a7a3..c90963cf 100644
--- a/shape.go
+++ b/shape.go
@@ -40,7 +40,7 @@ func parseFormatShapeSet(formatSet string) (*formatShape, error) {
 // print settings) and properties set. For example, add text box (rect shape)
 // in Sheet1:
 //
-//    f.AddShape("Sheet1", "G6", `{"type":"rect","color":{"line":"#4286F4","fill":"#8eb9ff"},"paragraph":[{"text":"Rectangle Shape","font":{"bold":true,"italic":true,"family":"Berlin Sans FB Demi","size":36,"color":"#777777","underline":"sng"}}],"width":180,"height": 90}`)
+//    err := f.AddShape("Sheet1", "G6", `{"type":"rect","color":{"line":"#4286F4","fill":"#8eb9ff"},"paragraph":[{"text":"Rectangle Shape","font":{"bold":true,"italic":true,"family":"Berlin Sans FB Demi","size":36,"color":"#777777","underline":"sng"}}],"width":180,"height": 90}`)
 //
 // The following shows the type of shape supported by excelize:
 //