Can you better explain the semantics of TestNG's @BeforeTest annotation?

I read the relevant documentation and didn't understand it. See als开发者_如何学JAVAo this question.

To understand that, you must understand testng.xml. Now reread the same thing,

The annotated method will be run before any test method belonging to the classes inside the <test> tag is run.

It should be clear that this annotation will only work with the methods those belong to the classes defined under <test> tag in testng.xml.