code: public void push(CmsFlexRequest req, CmsFlexResponse res) {
  
          m_flexRequestList.add(req);
          m_flexResponseList.add(res);
          m_flexContextInfoList.add(new CmsFlexRequestContextInfo());
          updateRequestContextInfo();
      }
docs: Adds another flex request/response pair to the stack.<p>
  
  @param req the request to add
  @param res the response to add