code: @RequestMapping(value = "/load", method = RequestMethod.GET)
      public Collection<RegistryCenterConfiguration> load(final HttpServletRequest request) {
          Optional<RegistryCenterConfiguration> regCenterConfig = regCenterService.loadActivated();
          if (regCenterConfig.isPresent()) {
              setRegistryCenterNameToSession(regCenterConfig.get(), request.getSession());
          }
          return regCenterService.loadAll().getRegistryCenterConfiguration();
      }
docs: 读取注册中心配置集合.
  
  @param request HTTP请求
  @return 注册中心配置集合