code: function(req, res) {
          var sId = req.urlParsed.file,
              session;
  
          if (sId === "")
              throw _errors.createInvalidReqMissingCommandParameterEH(req);
  
          session = _getSession(sId);
          if (session !== null) {
              res.success(sId, _sessions[sId].getCapabilities());
          } else {
              throw _errors.createInvalidReqVariableResourceNotFoundEH(req);
          }
      }
docs: private: