public void testEnums() {
    assertEqualInstance(EmptyEnum.class, null);
    assertEqualInstance(OneConstantEnum.class, OneConstantEnum.CONSTANT1);
    assertFreshInstance(TwoConstantEnum.class, 2);
    assertFreshInstance(new TypeToken<com.google.common.base.Optional<OneConstantEnum>>() {}, 2);
    assertFreshInstance(new TypeToken<List<OneConstantEnum>>() {}, 1);
    assertFreshInstance(new TypeToken<List<TwoConstantEnum>>() {}, 2);
  }

    assertNull(tester.instantiate(NoConstantEnum.class));
  }

  public void testInstantiate_oneConstantEnum() throws Exception {
    assertEquals(OneConstantEnum.A, tester.instantiate(OneConstantEnum.class));
  }

  public void testInstantiate_interface() throws Exception {
    assertNull(tester.instantiate(Runnable.class));
  }