Generic method with parameters vs. non-generic method with wildcards

Question

According to this entry in the Java Generics FAQ, there are some circumstances where a generic method has no equivalent non-generic method that uses wildcard types. According

Answer 1

Guess: The thing representing the first ? (ArrayList) does not 'implement' ArrayList (by virtue of the double nested wildcard). I know this sounds funny but....

Consider (for the original listing):

 void g(Class x) {} // Fail
 void g(Class x) {}  // Fail
 void g(Class

And

// Compiles
public class Test{
    > void f(ArrayList x) {}
    void g(ArrayList> x) {}

    void d(){
        ArrayList> d = new ArrayList>();
        f(d);
        g(d);
    }
}

This

// Does not compile on g(d)
public class Test{
    > void f(ArrayList x) {}
    void g(ArrayList> x) {}

    void d(){
        ArrayList d = new ArrayList();
        f(d);
        g(d);
    }
}