class IdentityMultimap {

  synchronized boolean removeKey(@NonNull final K key) {
    boolean removed = false;
    for (int index = 0; index < keysValues.length; index += 2) {
      if (keysValues[index] == key) {
        keysValues[index] = null;
        keysValues[index + 1] = null;
        removed = true;
      }
    }
    return removed;
  }

}