assertEquals(0, SessionSetupHandler.class.getDeclaredFields().length, "No fields expected");
        assertEquals(0, SessionSetupHandler.class.getDeclaredClasses().length, "No nested types expected");
    }

    @ParameterizedTest(name = "Implementation is instance: {0}")
    @MethodSource("implementations")

  // can reuse it.
  public static <E extends Enum<?> & Feature<?>> void assertGoodFeatureEnum(
      Class<E> featureEnumClass) {
    Class<?>[] classes = featureEnumClass.getDeclaredClasses();
    for (Class<?> containedClass : classes) {
      if (containedClass.getSimpleName().equals("Require")) {
        if (containedClass.isAnnotation()) {
          assertGoodTesterAnnotation(asAnnotation(containedClass));

  public void testFinalizeClassHasNoNestedClasses() throws Exception {
    // Ensure that the Finalizer class has no nested classes.
    // See https://github.com/google/guava/issues/1505
    assertThat(Finalizer.class.getDeclaredClasses()).isEmpty();
  }

  static class MyServerExampleWithFrq implements Closeable {
    private static final FinalizableReferenceQueue frq = new FinalizableReferenceQueue();