Extend from class

In Java, you can extend from a class like this:

public class Foo extends Bar {

    @Override
    public void print(String s) {
        System.out.println(s);
    }

}

In SpigotJS, you can also extend from classes, but a little different:

const CustomFoo = Java.extend(me.foo.Foo.class, {
    print: function(s) {
        print(s)
    }
})

Please note: You cant change constructors, only methods.