code: public void registerResolver(FeatureResolver resolver) {
          resolver.bind(this);
          featureResolvers.add(resolver);
          reverseResolvers.add(resolver);
          Collections.sort(featureResolvers, new LoadOrder());
          Collections.sort(reverseResolvers, new UnloadOrder());
      }
docs: 注册一个扩展特性解析器
  
  @param resolver 解析器