docs: public static Set<Field> getFields(Class<?> target, FieldFilter filter) {
          Class<?> clazz = target;
          Set<Field> fields = getDeclaredFields(clazz, filter);
          while((clazz = clazz.getSuperclass()) != null) {    
              fields.addAll(getDeclaredFields(clazz, filter));
          }
          return fields;
      }