code: public static ClassLoader getServiceClassLoader(String serviceUniqueName) {
          ClassLoader appClassLoader = SERVICE_CLASSLOADER_MAP.get(serviceUniqueName);
          if (appClassLoader == null) {
              return ClassLoaderUtils.getCurrentClassLoader();
          } else {
              return appClassLoader;
          }
      }
docs: 得到服务的自定义ClassLoader
  
  @param serviceUniqueName 服务唯一名称
  @return 服务级别ClassLoader