/** {@inheritDoc} */
 @SuppressWarnings({"SuspiciousMethodCalls"})
 public boolean retainAll(Collection<?> collection) {
   boolean modified = false;
   TLongIterator iter = iterator();
   while (iter.hasNext()) {
     if (!collection.contains(Long.valueOf(iter.next()))) {
       iter.remove();
       modified = true;
     }
   }
   return modified;
 }
 /** {@inheritDoc} */
 public boolean retainAll(TLongCollection collection) {
   if (this == collection) {
     return false;
   }
   boolean modified = false;
   TLongIterator iter = iterator();
   while (iter.hasNext()) {
     if (!collection.contains(iter.next())) {
       iter.remove();
       modified = true;
     }
   }
   return modified;
 }
 private long any(TLongSet nodes) {
   TLongIterator iterator = nodes.iterator();
   long id = iterator.next();
   iterator.remove();
   return id;
 }