I don't know if its bug or feature. but i sure know its fun! :)
Following the examples of ...
Normal Class
public class Main { public static void main(String[] args) { System.out.println("Boom"); } }
Empty main pattern
public class Main { static { System.out.println("Boom!!"); } public static void main(String[] args) { //do nothing } }
No main pattern
public class Main { static { System.out.println("Boom!!"); } }