return wrap((SetMultimap<?, ?>) delegate);
              }
            });
  }

  public void testEquals() {
    SetMultimap<Integer, String> map1 = ImmutableSetMultimap.of(1, "one");
    SetMultimap<Integer, String> map2 = ImmutableSetMultimap.of(2, "two");
    new EqualsTester()
        .addEqualityGroup(map1, wrap(map1), wrap(map1))
        .addEqualityGroup(map2, wrap(map2))
        .testEquals();
  }

import java.util.Collection;

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

  private EmptyImmutableSetMultimap() {
    super(ImmutableMap.of(), 0, null);
  }

  /*

import java.util.Collection;

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

  private EmptyImmutableSetMultimap() {
    super(ImmutableMap.of(), 0, null);
  }

  /*