return rowMap().keySet();
  }

  @Override
  public Set<C> columnKeySet() {
    return columnMap().keySet();
  }

  @Override
  public boolean containsValue(@Nullable Object value) {
    for (Map<C, V> row : rowMap().values()) {
      if (row.containsValue(value)) {
        return true;
      }
    }
    return false;
  }

  @Override

    assertNull(map.put(one, one));
    assertSame(one, map.get(one));
    assertTrue(map.containsKey(one));
    assertTrue(map.containsValue(one));
    Object two = new Object();
    assertSame(one, map.replace(one, two));
    assertTrue(map.containsKey(one));
    assertFalse(map.containsValue(one));
    Object three = new Object();
    assertTrue(map.replace(one, two, three));
    assertTrue(map.remove(one, three));

   */
  ALLOWS_NULL_KEY_QUERIES,
  ALLOWS_NULL_KEYS(ALLOWS_NULL_KEY_QUERIES),
  /**
   * The map does not throw {@code NullPointerException} on calls such as {@code
   * containsValue(null)}, {@code values().contains(null)} or {@code values().remove(null)}.
   */
  ALLOWS_NULL_VALUE_QUERIES,
  ALLOWS_NULL_VALUES(ALLOWS_NULL_VALUE_QUERIES),
  /**

    assertNull(segment.get(key, hash));
    assertFalse(segment.containsKey(key, hash));
    assertFalse(segment.containsValue(value));

    // count == 1
    segment.count++;
    assertSame(value, segment.get(key, hash));
    assertTrue(segment.containsKey(key, hash));
    assertTrue(segment.containsValue(value));
    // don't see absent values now that count > 0
    assertNull(segment.get(new Object(), hash));

    assertNull(segment.get(key, hash));
    assertFalse(segment.containsKey(key, hash));
    assertFalse(segment.containsValue(value));

    // count == 1
    segment.count++;
    assertSame(value, segment.get(key, hash));
    assertTrue(segment.containsKey(key, hash));
    assertTrue(segment.containsValue(value));
    // don't see absent values now that count > 0
    assertNull(segment.get(new Object(), hash));

          "Inverse should not contain key " + reversed.getKey(),
          inv.containsKey(reversed.getKey()));
      assertFalse(
          "Inverse should not contain value " + reversed.getValue(),
          inv.containsValue(reversed.getValue()));
      /*
       * TODO(cpovirk): This is a bit stronger than super.expectMissing(), which permits a <key,
       * someOtherValue> pair.
       */
      assertNull(

    return rowMap().keySet();
  }

  @Override
  public Set<C> columnKeySet() {
    return columnMap().keySet();
  }

  @Override
  public boolean containsValue(@Nullable Object value) {
    for (Map<C, V> row : rowMap().values()) {
      if (row.containsValue(value)) {
        return true;
      }
    }
    return false;
  }

  @Override

    for (ImmutableTable<Character, Integer, String> testInstance : getTestInstances()) {
      assertTrue(testInstance.containsValue("foo"));
      assertTrue(testInstance.containsValue("bar"));
      assertTrue(testInstance.containsValue("baz"));
      assertFalse(testInstance.containsValue("blah"));
    }
  }

  public void testIsEmpty() {

  }

  @Override
  public final boolean containsKey(@Nullable Object key) {
    return Maps.safeContainsKey(delegate, key);
  }

  @Override
  public final boolean containsValue(@Nullable Object value) {
    return delegate.containsValue(value);
  }

  @Override
  public @Nullable V get(@Nullable Object key) {
    return (key == null) ? null : Maps.safeGet(delegate, key);
  }

  @Override

abstract class AbstractMultimap<K extends @Nullable Object, V extends @Nullable Object>
    implements Multimap<K, V> {
  @Override
  public boolean isEmpty() {
    return size() == 0;
  }

  @Override
  public boolean containsValue(@Nullable Object value) {
    for (Collection<V> collection : asMap().values()) {
      if (collection.contains(value)) {
        return true;
      }
    }

    return false;
  }

  @Override