* #add(Object, int) add}{@code (element, 1)} instead.
   *
   * @param element the element to add one occurrence of; may be null only if explicitly allowed by
   *     the implementation
   * @return {@code true} always, since this call is required to modify the multiset, unlike other
   *     {@link Collection} types

  }

  /**
   * Adds the given element to this queue. If this queue has a maximum size, after adding {@code
   * element} the queue will automatically evict its greatest element (according to its comparator),
   * which may be {@code element} itself.
   *
   * @return {@code true} always
   */
  @CanIgnoreReturnValue
  @Override
  public boolean add(E element) {
    offer(element);
    return true;
  }

  /**
   * Returns a new array that prepends {@code element} to {@code array}.
   *
   * @param element the element to prepend to the front of {@code array}
   * @param array the array of elements to append
   * @return an array whose size is one larger than {@code array}, with {@code element} occupying
   *     the first position, and the elements of {@code array} occupying the remaining elements.
   */

            listener.warning(String.format("Unsupported HTML element <%s>", elementName));
            Element element = document.createElement("UNHANDLED-ELEMENT");
            element.appendChild(document.createTextNode(String.format("<%s>", elementName)));
            nodes.push(element);
            return true;
        }

        @Override
        public void onText(String text) {

        if (newLength > elements.length) {
          elements = Arrays.copyOf(elements, newLength);
        }
      }
      elements[n++] = element;
      return this;
    }

    /**
     * Adds each element of {@code elements} to the {@code ImmutableSortedSet}, ignoring duplicate
     * elements (only the first duplicate element is added).
     *
     * @param elements the elements to add

  // This reference is used both by the custom field serializer, and by the
  // GWT compiler to infer the elements of the lists that needs to be
  // serialized.
  //
  // Although this reference is non-final, it doesn't change after set creation.
  E element;

  SingletonImmutableSet(E element) {
    this.element = checkNotNull(element);
  }

  @Override
  public int size() {
    return 1;
  }

  @Override

    public int count(@Nullable Object element) {
      for (Entry<E> entry : entrySet()) {
        if (Objects.equal(entry.getElement(), element)) {
          return entry.getCount();
        }
      }
      return 0;
    }

    @Override
    public int add(E element, int occurrences) {
      checkArgument(occurrences >= 0);
      Integer frequency = backingMap.get(element);
      if (frequency == null) {

    public int count(@Nullable Object element) {
      for (Entry<E> entry : entrySet()) {
        if (Objects.equal(entry.getElement(), element)) {
          return entry.getCount();
        }
      }
      return 0;
    }

    @Override
    public int add(E element, int occurrences) {
      checkArgument(occurrences >= 0);
      Integer frequency = backingMap.get(element);
      if (frequency == null) {

    /**
     * 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(@Nullable Object element) {
      try {
        return unbox(countMap.get(element));
      } catch (NullPointerException | ClassCastException e) {
        return 0;

      return unfiltered.add(element, occurrences);
    }

    @Override
    public int remove(@CheckForNull Object element, int occurrences) {
      checkNonnegative(occurrences, "occurrences");
      if (occurrences == 0) {
        return count(element);
      } else {
        return contains(element) ? unfiltered.remove(element, occurrences) : 0;
      }