docs: function (cfg, cb) {
                  var appE = Aria.getClassRef("aria.core.environment.Customizations");
                  if (appE && appE.isCustomized() && !appE.descriptorLoaded()) {
                      // the application is customized but the descriptor hasn't been loaded yet: register to the event
                      appE.$onOnce({
                          'descriptorLoaded' : {
                              fn : this._startLoad,
                              scope : this,
                              args : {
                                  cfg : cfg,
                                  cb : cb
                              }
                          }
                      });
                  } else {
                      // no descriptor was specified, or it has already been loaded: go ahead
                      this._startLoad(null, {
                          cfg : cfg,
                          cb : cb
                      });
                  }
              }