code: function _setOptionChangeListener( Widget, els ) {
      if ( els.length > 0 && Widget.list ) {
          $( els ).on( 'changeoption', function() {
              // update (itemselect) picker on which event was triggered because the options changed
              new Collection( this ).update( Widget );
          } );
      }
  }
docs: Calls widget('update') on select-type widgets when the options change. This function is called upon initialization,
  and whenever a new repeat is created. In the latter case, since the widget('update') is called upon
  the elements of the repeat, there should be no duplicate eventhandlers.
  
  @param {{name: string}} widget   The widget configuration object
  @param {<Element>}      els      The array of elements that the widget has been instantiated on.