docs: function (appender) {
              var apps = this._appenders;
              for (var i = 0, l = apps.length; i < l; i++) {
                  if (!appender || apps[i] === appender) {
                      apps[i].$dispose();
                      apps.splice(i, 1);
                      i--;
                      l--;
                  }
              }
          }