針對不同Annotation提供了一些說明
@BeforeClass :- Run only 1 time before all the test cases of class. Can be used to initialize resources.
@AfterClass :- Run only 1 time after all the test cases of class. Can be used to clean up the resources.
@Before :- Run annotated method every time individual test case is executed but run before the test case.
@After :- Run annotated method every time individual test case is executed but run after the test case