from
http://forum.java.sun.com/thread.jsp?forum=316&thread=528605&tstart=0&trange=50

 In case of inheritance of interfaces, the name clash
is not reported

interface A<U,V> {
void m(U u,V v);
}

public interface I<T> extends A<Class<T>,Set<T>> {
//public void m(Class<T> c, Set<T> z);
public <Z extends T> void m(Class<Z> c, Set<Z> z);
}