public void clear() {
   super.clear();
   final int[] keys = this._set;
   final Object[] vals = this._values;
   final byte[] states = this._states;
   Arrays.fill(this._set, 0, this._set.length, 0);
   Arrays.fill(this._values, 0, this._values.length, null);
   Arrays.fill(this._states, 0, this._states.length, (byte) 0);
 }
 protected void removeAt(final int index) {
   this._values[index] = null;
   super.removeAt(index);
 }