ImmutableListMultimap<K, V> kvMultimap = (ImmutableListMultimap<K, V>) multimap;
      if (!kvMultimap.isPartialView()) {
        return kvMultimap;
      }
    }

    return fromMapEntries(multimap.asMap().entrySet(), null);
  }

  /**
   * Returns an immutable multimap containing the specified entries. The returned multimap iterates

    if (multimap.isEmpty() && valueComparator == null) {
      return of();
    }

    if (multimap instanceof ImmutableSetMultimap) {
      @SuppressWarnings("unchecked") // safe since multimap is not writable
      ImmutableSetMultimap<K, V> kvMultimap = (ImmutableSetMultimap<K, V>) multimap;
      if (!kvMultimap.isPartialView()) {
        return kvMultimap;
      }
    }

      ImmutableListMultimap<K, V> kvMultimap = (ImmutableListMultimap<K, V>) multimap;
      if (!kvMultimap.isPartialView()) {
        return kvMultimap;
      }
    }

    return fromMapEntries(multimap.asMap().entrySet(), null);
  }

  /**
   * Returns an immutable multimap containing the specified entries. The returned multimap iterates

   * {@code multimap}.
   */
  public <K extends K0, V extends V0> Multimap<K, V> build(
      Multimap<? extends K, ? extends V> multimap) {
    Multimap<K, V> result = build();
    result.putAll(multimap);
    return result;
  }

  /**
   * A specialization of {@link MultimapBuilder} that generates {@link ListMultimap} instances.
   *
   * @since 16.0
   */
  public abstract static class ListMultimapBuilder<

   * {@code multimap}.
   */
  public <K extends K0, V extends V0> Multimap<K, V> build(
      Multimap<? extends K, ? extends V> multimap) {
    Multimap<K, V> result = build();
    result.putAll(multimap);
    return result;
  }

  /**
   * A specialization of {@link MultimapBuilder} that generates {@link ListMultimap} instances.
   *
   * @since 16.0
   */
  public abstract static class ListMultimapBuilder<

    assertEquals(0, multimap().size());
    assertEmpty(multimap());
    assertEquals(multimap(), getSubjectGenerator().create());
    assertEmpty(multimap().entries());
    assertEmpty(multimap().asMap());
    assertEmpty(multimap().keySet());
    assertEmpty(multimap().keys());
    assertEmpty(multimap().values());
    for (K key : sampleKeys()) {
      assertGet(key);
    }
  }

  @MapFeature.Require(SUPPORTS_REMOVE)

  public void testPutAllIntoEmpty() {
    Multimap<K, V> target = getSubjectGenerator().create();
    assertEquals(!multimap().isEmpty(), target.putAll(multimap()));
    assertEquals(multimap(), target);
  }

  @MapFeature.Require(SUPPORTS_PUT)
  public void testPutAll() {
    Multimap<K, V> source =
        getSubjectGenerator().create(mapEntry(k0(), v3()), mapEntry(k3(), v3()));
    assertTrue(multimap().putAll(source));

    } catch (UnsupportedOperationException expected) {
    }
    assertMultimapRemainsUnmodified(multimap, originalEntries);

    // Test #putAll(Multimap<K, V>)
    Multimap<K, V> multimap2 = ArrayListMultimap.create();
    multimap2.put(sampleKey, sampleValue);
    try {
      multimap.putAll(multimap2);
      fail("putAll(Multimap<K, V>) succeeded on unmodifiable multimap");

    TreeMultimap<String, Integer> multimap = TreeMultimap.create();
    multimap.put("google", 2);
    multimap.put("google", 6);
    multimap.put("foo", 3);
    multimap.put("foo", 1);
    multimap.put("foo", 7);
    multimap.put("tree", 4);
    multimap.put("tree", 0);
    return multimap;
  }

  public void testToString() {
    SetMultimap<String, Integer> multimap = create();

  protected Multimap<String, Integer> create() {
    Multimap<String, Integer> unfiltered = HashMultimap.create();
    unfiltered.put("foo", 55556);
    unfiltered.put("badkey", 1);
    return Multimaps.filterEntries(unfiltered, ENTRY_PREDICATE);
  }

  private static final Predicate<String> KEY_PREDICATE = key -> !Objects.equals(key, "badkey");

  public void testFilterKeys() {