code: protected void droppedLock (final NodeObject.Lock lock)
      {
          _nodeobj.removeFromLocks(lock);
          _stats.locksHijacked++;
          _dropobs.apply(new ObserverList.ObserverOp<DroppedLockObserver>() {
              public boolean apply (DroppedLockObserver observer) {
                  observer.droppedLock(lock);
                  return true;
              }
          });
      }
docs: Called when we have been forced to drop a lock.