class G12 { /* interface Collection { boolean contains( Object o ); boolean containsAll( Collection c ); boolean removeAll( Collection c ); boolean retainAll( Collection c ); // etc. } */ interface Collection<E> { boolean contains( Object o ); boolean containsAll( Collection<?> c ); boolean removeAll( Collection<?> c ); boolean retainAll( Collection<?> c ); // <T> boolean containsAll( Collection<T> c ); // <T> boolean removeAll( Collection<T> c ); // <T> boolean retainAll( Collection<T> c ); // etc. } }