input: Write a python function to create a simple PyQt5 text editor application.
  assert isinstance(window, Editor)
  assert window.windowTitle() == "Text Editor"
  assert window.text.toPlainText() == ""
output: from PyQt5.QtWidgets import QApplication, QMainWindow, QTextEdit
  
  class Editor(QMainWindow):
      def __init__(self):
          super().__init__()
          self.initUI()
          
      def initUI(self):
          self.text = QTextEdit(self)
          self.setCentralWidget(self.text)
          self.setWindowTitle("Text Editor")
          self.setGeometry(100, 100, 800, 600)
  
  def create_text_editor():
      app = QApplication([])
      window = Editor()
      window.show()
      return window