docs: private static int classPriority(Class<?> o1) {
      Priority p = o1.getAnnotation(Priority.class);
      if(p == null) {
        Class<?> pa = o1.getDeclaringClass();
        p = (pa != null) ? pa.getAnnotation(Priority.class) : null;
      }
      return p != null ? p.value() : Priority.DEFAULT;
    }