code: function (request, xhr, callback) {
  
              var model = request.model;
  
              if (this._parsePayloadOnUpdate(request, xhr)) {
                  this._parseModelPayload(xhr, model, request.options);
              }
  
              if (callback) {
                  callback(null, model, request.options);
              }
          }
docs: *
  
  @param request.url
  @param request.queryParameter
  @param request.model
  @param request.options
  @param xhr
  @param callback