* iterator will be left exhausted: its {@code hasNext()} method will return {@code false}.
   *
   * @param removeFrom the iterator to (potentially) remove elements from
   * @param elementsToRemove the elements to remove
   * @return {@code true} if any element was removed from {@code iterator}
   */
  @CanIgnoreReturnValue

   * <a href="https://github.com/google/guava/wiki/CollectionUtilitiesExplained#comparators">{@code
   * Comparators}</a>.
   *
   * @param a first value to compare, returned if less than or equal to b.
   * @param b second value to compare.
   * @throws ClassCastException if the parameters are not <i>mutually comparable</i>.
   * @since 30.0
   */

   *
   * <p>The iteration order of the returned set follows the enum's iteration order, not the order in
   * which the elements are provided to the method.
   *
   * @param anElement one of the elements the set should contain
   * @param otherElements the rest of the elements the set should contain
   * @return an immutable set containing those elements, minus duplicates
   */

        add(element);
      }
      return this;
    }

    /**
     * Adds a number of occurrences of an element to this {@code ImmutableSortedMultiset}.
     *
     * @param element the element to add
     * @param occurrences the number of occurrences of the element to add. May be zero, in which
     *     case no change will be made.
     * @return this {@code Builder} object

   * returned by {@code factory}. Those objects should not be manually updated and they should not
   * use soft, weak, or phantom references.
   *
   * @param map place to store the mapping from each key to its corresponding values
   * @param factory supplier of new, empty collections that will each hold all values for a given
   *     key
   * @throws IllegalArgumentException if {@code map} is not empty
   */

      return this;
    }

    /**
     * Adds a number of occurrences of an element to this {@code ImmutableMultiset}.
     *
     * @param element the element to add
     * @param occurrences the number of occurrences of the element to add. May be zero, in which
     *     case no change will be made.
     * @return this {@code Builder} object
     * @throws NullPointerException if {@code element} is null

   * must be well-behaved with respect to {@link Object#equals} and {@link Object#hashCode}.
   *
   * @param left the map to treat as the "left" map for purposes of comparison
   * @param right the map to treat as the "right" map for purposes of comparison
   * @param valueEquivalence the equivalence relationship to use to compare values
   * @return the difference between the two maps
   * @since 10.0
   */

     * contains {@code element}, then {@code add} has no effect (only the previously added element
     * is retained).
     *
     * @param element the element to add
     * @return this {@code Builder} object
     * @throws NullPointerException if {@code element} is null
     */
    @CanIgnoreReturnValue
    @Override

     * already contains {@code element}, then {@code add} has no effect. (only the previously added
     * element is retained).
     *
     * @param element the element to add
     * @return this {@code Builder} object
     * @throws NullPointerException if {@code element} is null
     */
    @CanIgnoreReturnValue
    @Override

  }

  /**
   * Returns an immutable multiset entry with the specified element and count. The entry will be
   * serializable if {@code e} is.
   *
   * @param e the element to be associated with the returned entry
   * @param n the count to be associated with the returned entry
   * @throws IllegalArgumentException if {@code n} is negative
   */