code: function getConversationId(req, res, options) {
      var cookieName = options.conversationIdCookieName;
      var headerName = options.conversationIdHeader;
      var conversationId = req.headers[headerName] || req.cookies && req.cookies[cookieName];
      if (!conversationId) {
          conversationId = uuid.v1();
      }
      req.conversationId = conversationId;
      res.cookie(cookieName, conversationId, { path: '/' });
      return conversationId;
  }
docs: Create a "conversation" identifier to track requests per browser session