Anonymous overloading in Java

Test.java

package com.github.fge.uritemplate;

public final class Test
{
    public static class A
    {
        public static final int x = 1;

        public int m(A a, B b)
        {
            return a.m(b, b) + x;
        }
    }

    public static class B
        extends A
    {
        public int m(A a1, B a2)
        {
            if (a1 == a2)
                return x;
            return super.m(a1, a2);
        }
    }

    public static void main(final String... args)
    {
        B b1 = new B()
        {
            int m(B a, B b)
            {
                return 10;
            }
        };
        System.out.println(b1.m(b1, b1));    // prints 1
        System.out.println(new B() {
            int m(B a, B b) { return 10; }
        }.m(null, null));                    // prints 10
    }
}