}

  public void testEqualsForEmptyMap() {
    Map<K, V> map;
    try {
      map = makeEmptyMap();
    } catch (UnsupportedOperationException e) {
      return;
    }

    // Explicitly call `equals`; `assertEquals` might return fast
    assertTrue(map.equals(map));
    assertTrue(makeEmptyMap().equals(map));
    assertEquals(emptyMap(), map);
    assertFalse(map.equals(emptySet()));

    }

    abstract Table<Character, String, Integer> makeTable();

    @Override
    protected Map<String, Integer> makeEmptyMap() {
      return makeTable().row('a');
    }

    @Override
    protected Map<String, Integer> makePopulatedMap() {
      Table<Character, String, Integer> table = makeTable();

        @Override
        public boolean retainAll(Collection<?> c) {
          return delegate.entrySet().retainAll(c);
        }
      };
    }
  }

  @Override
  protected Map<String, String> makeEmptyMap() {
    Map<String, Integer> underlying = new HashMap<>();
    return transformValues(
        new UnmodifiableIteratorMap<String, Integer>(underlying), Functions.toStringFunction());
  }

  @Override