shadowConstants.add(result.get());
    }
    assertEquals(ImmutableSet.<Object>copyOf(shadowTestEnum.getEnumConstants()), shadowConstants);
    Optional<TestEnum> result = Enums.getIfPresent(shadowTestEnum, "blibby");
    assertThat(result).isAbsent();
    return new WeakReference<>(shadowLoader);
  }

  @GwtIncompatible // stringConverter
  public void testStringConverter_convert() {