assertTrue(entrySet.contains(mapEntry(entry.getKey(), oldValue)));
    assertEquals(oldValue, map.get(entry.getKey()));
    assertInvariants(map);
  }

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