* multiset for every occurrence in {@code c}, see {@link Multisets#retainOccurrences(Multiset,
   * Multiset)}.
   *
   * <p>This method refines {@link Collection#retainAll} to further specify that it <b>may not</b>
   * throw an exception in response to any of {@code elements} being null or of the wrong type.
   *
   * @see Multisets#retainOccurrences(Multiset, Multiset)
   */
  @CanIgnoreReturnValue
  @Override

   * multiset for every occurrence in {@code c}, see {@link Multisets#retainOccurrences(Multiset,
   * Multiset)}.
   *
   * <p>This method refines {@link Collection#retainAll} to further specify that it <b>may not</b>
   * throw an exception in response to any of {@code elements} being null or of the wrong type.
   *
   * @see Multisets#retainOccurrences(Multiset, Multiset)
   */
  @CanIgnoreReturnValue
  @Override

   * other elements.
   *
   * @return {@code true} if {@code multisetToModify} was changed as a result of this operation
   * @since 10.0
   */
  @CanIgnoreReturnValue
  public static boolean retainOccurrences(
      Multiset<?> multisetToModify, Multiset<?> multisetToRetain) {
    return retainOccurrencesImpl(multisetToModify, multisetToRetain);
  }

  /** Delegate implementation which cares about the element type. */

   * other elements.
   *
   * @return {@code true} if {@code multisetToModify} was changed as a result of this operation
   * @since 10.0
   */
  @CanIgnoreReturnValue
  public static boolean retainOccurrences(
      Multiset<?> multisetToModify, Multiset<?> multisetToRetain) {
    return retainOccurrencesImpl(multisetToModify, multisetToRetain);
  }

  /** Delegate implementation which cares about the element type. */