Generic Class vs generic method

package main;

interface MyGenericInterface<X, Y> {
    // Now the generic types X, and Y are defined in the scope of this entire interface and we can use them
    X awesomeMethod(Y argument);  // awesomeMethod will return something of type X, which is still unknown at this point
}

interface MyNormalInterface {
    <X,Y> X coolMethod(MyGenericInterface<X,Y> generic, Y argument);

    // Here we define the generics in the declaration of a method. The generic types X and Y can only be used in
    // the context of this method.
    // Trying to create another abstract method like this will fail:
    // X anotherMethod(Y arg);
    // because the generics X and Y are not defined here

    // The interface is implemented without resolving the generics
}

class MyClassOne implements MyGenericInterface<Void, String>{
    // Classes that implement the generic interface should resolve these generics to actual classes
    @Override
    public Void awesomeMethod(String argument) {
        System.out.println(argument);
        return null;
    }
}

class MyClassTwo implements MyNormalInterface{
    // Classes that implement the interface that doesn't have generics itself but some methods do don't resolve the
    // generics.

    @Override
    public <X, Y> X coolMethod(MyGenericInterface<X, Y> generic, Y argument) {
        return generic.awesomeMethod(argument);
    }
    // Here we need to define the generics again for this method, because they weren't defined by the class, but we need
    // them for this method. Define them like we did in the interface.

    // When calling this method with a concrete class that implements MyGenericInterface (and has therefor resolved the
    // generics), the generics will be resolved for this method. For example, with a MyClassOne X will become Void and
    // Y will become String.
}

class Main2{
    public static void main(String[] args){
        MyClassOne classOne = new MyClassOne();  // aka Visitor
        MyClassTwo classTwo = new MyClassTwo();  // aka Visitable
        classTwo.coolMethod(classOne, "Hello World!");
        // OUTPUT:
        // Hello World!
    }
}