add one java file

DemoApplicationTests.java

@@ -0,0 +1,16 @@
+package com.example.demo;
+//testing add (lizan in 2021)
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest
+public class DemoApplicationTests {
+
+    @Test
+    public void contextLoads() {
+    }
+
+}