@Test
  public void testOptionalOptional_empty() {
    OptionalOptional empty = OptionalOptional.builder().build();
    Truth.assertThat(empty.maybeJustMaybe()).isEmpty();
  }
Tests that an annotation on a type parameter of an {@code @AutoValue} builder is copied to the
implementation class.
value/src/it/functional/src/test/java/com/google/auto/value/AutoValueJava8Test.java