@Override
    public void clear() {
      throw new UnsupportedOperationException();
    }

    @Override
    public int setCount(@ParametricNullness E element, int count) {
      throw new UnsupportedOperationException();
    }

    @Override
    public boolean setCount(@ParametricNullness E element, int oldCount, int newCount) {
      throw new UnsupportedOperationException();
    }

   * @deprecated Unsupported operation.
   */
  @CanIgnoreReturnValue
  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  public final int setCount(E element, int count) {
    throw new UnsupportedOperationException();
  }

  /**
   * Guaranteed to throw an exception and leave the collection unmodified.
   *

     * We keep an array of elements and counts.  Periodically -- when we need more room in the
     * array, or when we're building, or the like -- we sort, deduplicate, and combine the counts.
     * Negative counts indicate a setCount operation with ~counts[i].
     */

    private final Comparator<? super E> comparator;

    @VisibleForTesting E[] elements;
    private int[] counts;

    /*