EXample:

    public enum Test {

        FOO {},
        BAR,
        BAZ;

        public abstract void f();
    }

Invoking CC within the empty pair of braces and selecting "f() - implement" results in:

    public enum Test {

        FOO {},
        BAR,
        BAZ;
    FOO {

            @Override
            public void f()
            {
                throw new UnsupportedOperationException("Not supported yet.");
            }
     },
        BAR,
        BAZ;

        public abstract void f();
    }