@SuppressWarnings("unchecked")
 protected void reset(int newLevel) {
   super.reset(newLevel);
   keys = new Value[len];
   values = (V[]) new Object[len];
 }
 @Override
 protected void reset(int newLevel) {
   super.reset(newLevel);
   keys = new int[len];
   values = new int[len];
 }