* Implementation of {@link ImmutableListMultimap} with no entries.
 *
 * @author Jared Levy
 */
@GwtCompatible
final class EmptyImmutableListMultimap extends ImmutableListMultimap<Object, Object> {
  static final EmptyImmutableListMultimap INSTANCE = new EmptyImmutableListMultimap();

  private EmptyImmutableListMultimap() {
    super(ImmutableMap.<Object, ImmutableList<Object>>of(), 0);
  }

  /*

   */
  // Casting is safe because the multimap will never hold any elements.
  @SuppressWarnings("unchecked")
  public static <K, V> ImmutableListMultimap<K, V> of() {
    return (ImmutableListMultimap<K, V>) EmptyImmutableListMultimap.INSTANCE;
  }

  /** Returns an immutable multimap containing a single entry. */
  public static <K, V> ImmutableListMultimap<K, V> of(K k1, V v1) {

   */
  // Casting is safe because the multimap will never hold any elements.
  @SuppressWarnings("unchecked")
  public static <K, V> ImmutableListMultimap<K, V> of() {
    return (ImmutableListMultimap<K, V>) EmptyImmutableListMultimap.INSTANCE;
  }

  /** Returns an immutable multimap containing a single entry. */
  public static <K, V> ImmutableListMultimap<K, V> of(K k1, V v1) {