code: function dbCreateError(tx, err) {
              if (calledDbCreateError) {
                  return;
              }
              err = idbModules.util.findError(arguments);
              calledDbCreateError = true;
              var evt = idbModules.util.createEvent("error", arguments);
              req.readyState = "done";
              req.error = err || "DOMError";
              idbModules.util.callback("onerror", req, evt);
          }
docs: cast to a string