code: public static Set<Method> getMethodsAnnotatedBy(
        Class<?> classs, Class<? extends Annotation> ann) {
      Set<Method> set = new HashSet<>();
      for (Method method : getAllMethods(classs)) {
        if (method.isAnnotationPresent(ann)) {
          set.add(method);
        }
      }
      return set;
    }
docs: Gets all methods annotated by annotation.
  
  @param classs class to get fields from
  @param ann    annotation that must be present on the method
  @return set of methods