* dummy version.
   *
   * @throws UnsupportedOperationException always
   * @deprecated <b>Pass the parameters of type {@code Comparable} to use {@link
   *     ImmutableSortedSet#of(Comparable, Comparable)}.</b>
   */
  @DoNotCall("Pass parameters of type Comparable")
  @Deprecated
  public static <E> ImmutableSortedSet<E> of(E e1, E e2) {
    throw new UnsupportedOperationException();
  }

   * {@code lexicographical(Collections.reverseOrder(comparator))} (consider how each would order
   * {@code [1]} and {@code [1, 1]}).
   */
  // Note: 90% of the time we don't add type parameters or wildcards that serve only to "tweak" the
  // desired return type. However, *nested* generics introduce a special class of problems that we
  // think tip it over into being worthwhile.

  /**
   * Returns an immutable set of the values for the given key. If no mappings in the multimap have
   * the provided key, an empty immutable set is returned. The values are in the same order as the
   * parameters used to build this multimap.
   */
  @Override
  public ImmutableSet<V> get(K key) {
    // This cast is safe as its type is known in constructor.
    ImmutableSet<V> set = (ImmutableSet<V>) map.get(key);

   *
   * @param iterator the iterator whose minimum element is to be determined
   * @throws NoSuchElementException if {@code iterator} is empty
   * @throws ClassCastException if the parameters are not <i>mutually comparable</i> under this
   *     ordering.
   * @since 11.0
   */
  @ParametricNullness
  public <E extends T> E min(Iterator<E> iterator) {

   * }
   * }</pre>
   *
   * @return {@code true} if {@code multisetToModify} was changed as a result of this operation
   * @since 18.0 (present in 10.0 with a requirement that the second parameter be a {@code
   *     Multiset})
   */
  @CanIgnoreReturnValue
  public static boolean removeOccurrences(
      Multiset<?> multisetToModify, Iterable<?> occurrencesToRemove) {

  /**
   * Returns an immutable list of the values for the given key. If no mappings in the multimap have
   * the provided key, an empty immutable list is returned. The values are in the same order as the
   * parameters used to build this multimap.
   */
  @Override
  public ImmutableList<V> get(K key) {
    // This cast is safe as its type is known in constructor.
    ImmutableList<V> list = (ImmutableList<V>) map.get(key);

     *   `map.getOrDefault(FOO_KEY, defaultValue)`
     *
     * - a call that consults a chain of maps, as in `mapA.getOrDefault(key, mapB.getOrDefault(key,
     *   ...))`
     *
     * So it makes sense for the parameter (and thus the return type) to be @CheckForNull.
     *
     * Two other points:
     *
     * 1. We'll want to use something like @PolyNull once we can make that work for the various
     * platforms we target.

   * Comparable} element.</b> Proper calls will resolve to the version in {@code
   * ImmutableSortedMultiset}, not this dummy version.
   *
   * @throws UnsupportedOperationException always
   * @deprecated <b>Pass the parameters of type {@code Comparable} to use {@link
   *     ImmutableSortedMultiset#of(Comparable, Comparable)}.</b>
   */
  @DoNotCall("Elements must be Comparable. (Or, pass a Comparator to orderedBy or copyOf.)")
  @Deprecated

   */
  public static <C extends @Nullable Object, K extends C, V extends @Nullable Object>
      TreeMap<K, V> newTreeMap(@CheckForNull Comparator<C> comparator) {
    // Ideally, the extra type parameter "C" shouldn't be necessary. It is a
    // work-around of a compiler type inference quirk that prevents the
    // following code from being compiled:
    // Comparator<Class<?>> comparator = null;

 *     source-compatible</a> since 4.0)
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
/*
 * The type parameter is <T> rather than <T extends @Nullable> so that we can use T in the
 * doEquivalent and doHash methods to indicate that the parameter cannot be null.
 */
public abstract class Equivalence<T>
{
  /** Constructor for use by subclasses. */
  protected Equivalence() {}

  /**