/** {@inheritDoc} */
  public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
    // VERSION
    in.readByte();

    // SUPER
    super.readExternal(in);

    // NUMBER OF ENTRIES
    int size = in.readInt();
    setUp(size);

    // ENTRIES
    while (size-- > 0) {
      int key = in.readInt();
      int val = in.readInt();
      put(key, val);
    }
  }