ms.add(Color.BLUE, 3);
    ms.add(Color.YELLOW, 1);
    ms.add(Color.RED, 2);
    assertEquals("[BLUE x 3, RED x 2, YELLOW]", ms.toString());
  }

  @GwtIncompatible // SerializableTester
  public void testSerializable() {
    Multiset<Color> ms = EnumMultiset.create(asList(Color.RED, Color.YELLOW, Color.RED));
    assertEquals(ms, SerializableTester.reserialize(ms));
  }

  public void testEntrySet() {

    uniqueEntries.addAll(bimap.entrySet());
    assertEquals(3, uniqueEntries.size());
  }

  @J2ktIncompatible
  @GwtIncompatible // serialize
  public void testSerializable() {
    SerializableTester.reserializeAndAssert(EnumHashBiMap.create(Currency.class));
  }

  @J2ktIncompatible
  @GwtIncompatible // reflection
  public void testNulls() {