}

  /**
   * A sensible, albeit inefficient, definition of {@link #size} in terms of {@link #entrySet}. If
   * you override {@link #entrySet}, you may wish to override {@link #size} to forward to this
   * implementation.
   *
   * @since 7.0
   */
  protected int standardSize() {
    return Multisets.linearTimeSizeImpl(this);
  }

  /**

         * requireNonNull is safe because the callers promise to put non-null objects in the first
         * `length` array elements.
         */
        @SuppressWarnings("unchecked") // our callers put only E instances into the array
        E onlyElement = (E) requireNonNull(elements[0]);
        return of(onlyElement);
      default:
        /*
         * The suppression is safe because the callers promise to put non-null objects in the first

   *     the {@link ExecutionException} thrown by {@code input.get()} or, if {@code get()} throws a
   *     different kind of exception, that exception itself. To avoid hiding bugs and other
   *     unrecoverable errors, callers should prefer more specific types, avoiding {@code
   *     Throwable.class} in particular.
   * @param fallback the {@link Function} to be called if the input fails with the expected

   * removeAll}{@code (occurrencesToRemove)}, which removes all occurrences of elements that appear
   * in {@code occurrencesToRemove}. However, this operation <i>is</i> equivalent to, albeit
   * sometimes more efficient than, the following:
   *
   * <pre>{@code
   * for (E e : occurrencesToRemove) {
   *   multisetToModify.remove(e);
   * }
   * }</pre>
   *

   * available for all platforms and configurations. If that implementation is unavailable, this
   * method falls back to {@code getStackTrace}. Callers that require the special implementation can
   * check its availability with {@link #lazyStackTraceIsLazy()}.
   *
   * <p>The expected (but not guaranteed) performance of the special implementation differs from

   * available for all platforms and configurations. If that implementation is unavailable, this
   * method falls back to {@code getStackTrace}. Callers that require the special implementation can
   * check its availability with {@link #lazyStackTraceIsLazy()}.
   *
   * <p>The expected (but not guaranteed) performance of the special implementation differs from

   * builders only ever accumulate entries it will always be valid to throw from buildOrThrow() with
   * the first duplicate.
   */

  // This entry point is for callers other than ImmutableMap.Builder.
  static <K, V> RegularImmutableMap<K, V> create(
      int n, @Nullable Object[] alternatingKeysAndValues) {
    return create(n, alternatingKeysAndValues, /* builder= */ null);
  }

        node.previousSibling = keyTail;
        keyList.tail = node;
      }
    } else { // non-empty list, insert before nextSibling
      /*
       * requireNonNull is safe as long as callers pass a nextSibling that (a) has the same key and
       * (b) is present in the multimap. (And they do, except maybe in case of concurrent
       * modification, in which case all bets are off.)
       */

    return !iterable.iterator().hasNext();
  }

  /**
   * Returns an iterable over the merged contents of all given {@code iterables}. Equivalent entries
   * will not be de-duplicated.
   *
   * <p>Callers must ensure that the source {@code iterables} are in non-descending order as this
   * method does not sort its input.
   *
   * <p>For any equivalent elements across all {@code iterables}, it is undefined which element is

 * supertype of `Function<A, B>` turns out to be massively more useful to callers in practice: They
 * want their output to be non-null in operations like `stream.map(myConverter)`, and we can
 * guarantee that as long as we also require the input type to be non-null[*] (which is a
 * requirement that existing callers already fulfill).
 *
 * Disclaimer: Part of the reason that callers are so well adapted to `Function<A, B>` may be that