@Override
  public ImmutableSet<String> getSupportedAnnotationTypes() {
    return ImmutableSet.of(
        AutoFactory.class.getCanonicalName(),
        Provided.class.getCanonicalName(),
        AnnotationsToApply.class.getCanonicalName());
  }
Checks that {@link AnnotationsToApply} is used correctly.
factory/src/main/java/com/google/auto/factory/processor/AutoFactoryProcessor.java