Executing test with multiple methods with TestNG

In my attachment, it can be seen that there is a test which needs a separate method [b:1qp028d8]isPresent[/b:1qp028d8] which is called in main() method.

While executing such tests with multiple calls, I need to use public static void main() and run it using Java application. How can we use TestNG to call and use mutiple methods?

Attaching java code as well.