public boolean addAll(Collection c) {
   return getIntCollection().addAll(CollectionIntCollection.wrap(c));
 }
 public boolean containsAll(Collection c) {
   return getIntCollection().containsAll(CollectionIntCollection.wrap(c));
 }
 public boolean retainAll(Collection c) {
   return getIntCollection().retainAll(CollectionIntCollection.wrap(c));
 }