code: function cancelRestRequests(category) {
      _.each(restXhrPool, function (xhr) {
          if (category && (!xhr.girder || !xhr.girder[category])) {
              return;
          }
          if (xhr.abort) {
              xhr.abort();
          }
      });
  }
docs: /* Cancel outstanding rest requests.
  :param category: if specified, only abort those requests that have
  xhr.girder[category] set to a truthy value.