* add(Object)} call will throw a {@code ClassCastException}.
   *
   * <p>The type specification is {@code <E extends Comparable>}, instead of the more specific
   * {@code <E extends Comparable<? super E>>}, to support classes defined without generics.
   */
  @SuppressWarnings("rawtypes") // https://github.com/google/guava/issues/989
  public static <E extends Comparable> TreeMultiset<E> create() {
    return new TreeMultiset<>(Ordering.natural());

   * natural ordering. The sorted sets use {@link Ordering#natural()} as the comparator. This method
   * provides more type-safety than {@link #builder}, as it can be called only for classes that
   * implement {@link Comparable}.
   */
  public static <E extends Comparable<?>> Builder<E> naturalOrder() {
    return new Builder<>(Ordering.natural());
  }

  /**

  Object writeReplace() {
    return super.writeReplace();
  }

  // This class is never actually serialized directly, but we have to make the
  // warning go away (and suppressing would suppress for all nested classes too)
  @J2ktIncompatible // serialization
  private static final long serialVersionUID = 0;

 * object.
 *
 * <p><b>Comparison to {@code java.util.Optional} (JDK 8 and higher):</b> A new {@code Optional}
 * class was added for Java 8. The two classes are extremely similar, but incompatible (they cannot
 * share a common supertype). <i>All</i> known differences are listed either here or with the
 * relevant methods below.
 *
 * <ul>

      return new Failure(t);
    }
  }

  /**
   * An inlined private copy of {@link Uninterruptibles#getUninterruptibly} used to break an
   * internal dependency on other /util/concurrent classes.
   */
  @ParametricNullness
  private static <V extends @Nullable Object> V getUninterruptibly(Future<V> future)
      throws ExecutionException {
    boolean interrupted = false;
    try {

 * methods or inner class constructors, the created object uses itself as the synchronization mutex.
 *
 * <p>This class should be used by other collection classes only.
 *
 * @author Mike Bostock
 * @author Jared Levy
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
/*

   * natural ordering. The sorted sets use {@link Ordering#natural()} as the comparator. This method
   * provides more type-safety than {@link #builder}, as it can be called only for classes that
   * implement {@link Comparable}.
   */
  public static <E extends Comparable<?>> Builder<E> naturalOrder() {
    return new Builder<>(Ordering.natural());
  }

  /**

    int getHash();

    /** Gets the key for this entry. */
    K getKey();

    /** Gets the value for the entry. */
    V getValue();
  }

  /*
   * Note: the following classes have a lot of duplicate code. It sucks, but it saves a lot of
   * memory. If only Java had mixins!
   */

  /** Base class for {@link InternalEntry} implementations for strong keys. */

 * appropriate primitive specialization such as {@code IntSupplier}) instead whenever possible.
 * Otherwise, at least reduce <i>explicit</i> dependencies on this type by using lambda expressions
 * or method references instead of classes, leaving your code easier to migrate in the future.
 *
 * <p>To use an existing supplier instance (say, named {@code supplier}) in a context where the

  }

  /**
   * Creates a new {@code ListMultimap} that uses the provided map and factory. It can generate a
   * multimap based on arbitrary {@link Map} and {@link List} classes.
   *
   * <p>The {@code factory}-generated and {@code map} classes determine the multimap iteration
   * order. They also specify the behavior of the {@code equals}, {@code hashCode}, and {@code