return NOT_FOUND;
    }

    Object oldValue = value(index);

    moveLastEntry(index, mask);
    size--;
    incrementModCount();

    return oldValue;
  }

  /**
   * Moves the last entry in the entry array into {@code dstIndex}, and nulls out its old position.
   */
  void moveLastEntry(int dstIndex, int mask) {
    Object table = requireTable();
    int[] entries = requireEntries();

            /* values= */ null);
    if (index == -1) {
      return false;
    }

    moveLastEntry(index, mask);
    size--;
    incrementModCount();

    return true;
  }

  /**
   * Moves the last entry in the entry array into {@code dstIndex}, and nulls out its old position.
   */
  void moveLastEntry(int dstIndex, int mask) {
    Object table = requireTable();
    int[] entries = requireEntries();

      return NOT_FOUND;
    }

    Object oldValue = value(index);

    moveLastEntry(index, mask);
    size--;
    incrementModCount();

    return oldValue;
  }

  /**
   * Moves the last entry in the entry array into {@code dstIndex}, and nulls out its old position.
   */
  void moveLastEntry(int dstIndex, int mask) {
    Object table = requireTable();
    int[] entries = requireEntries();