@Override
public boolean equals(Object obj) {
if (!(obj instanceof HashableWeakReference)) return false;
U referent = super.get();
@SuppressWarnings("unchecked")
Object other = ((HashableWeakReference<?>) obj).get();
if (referent == null) return other == null;
return referent.equals(other);
}
@Override
public boolean equals(Object obj) {
return referent.equals(obj);
}