}

  // Query Operations

  /**
   * Returns the number of occurrences of {@code element} in this multiset.
   *
   * @param element the element to look for
   * @return the nonnegative number of occurrences of the element
   */
  @Override
  public int count(@CheckForNull Object element) {
    AtomicInteger existingCounter = safeGet(countMap, element);

   */
  @CanIgnoreReturnValue
  public static int advance(Iterator<?> iterator, int numberToAdvance) {
    checkNotNull(iterator);
    checkArgument(numberToAdvance >= 0, "numberToAdvance must be nonnegative");

    int i;
    for (i = 0; i < numberToAdvance && iterator.hasNext(); i++) {
      iterator.next();
    }
    return i;
  }

  /**