What I had in mind was something like this:

private void invokeValidatorsOnMethods(List<Throwable> errors) {
  Map<Annotation, List<FrameworkMethod>> annotationMap = getTestClass.getAnnotationToMethods();
  for (Annotation a : annotationMap.keySet()) {
    if (hasValidatorAnnotation(a)) {
      for (FrameworkMethod m : annotationMap.get(a)) {
        invokeValidatorsOnMethod(a, m, errors);
      }
    }
  }
}