code: @Override
      public ListSubscribedRuleGroupsResult listSubscribedRuleGroups(ListSubscribedRuleGroupsRequest request) {
          request = beforeClientExecution(request);
          return executeListSubscribedRuleGroups(request);
      }
docs: <p>
  Returns an array of <a>RuleGroup</a> objects that you are subscribed to.
  </p>
  
  @param listSubscribedRuleGroupsRequest
  @return Result of the ListSubscribedRuleGroups operation returned by the service.
  @throws WAFNonexistentItemException
  The operation failed because the referenced object doesn't exist.
  @throws WAFInternalErrorException
  The operation failed because of a system problem, even though the request was valid. Retry your request.
  @sample AWSWAFRegional.ListSubscribedRuleGroups
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/waf-regional-2016-11-28/ListSubscribedRuleGroups"
  target="_top">AWS API Documentation</a>