code: function init( $group, opts = {} ) {
      if ( !this.form ) {
          throw new Error( 'Widgets module not correctly instantiated with form property.' );
      }
  
      options = opts;
      formHtml = this.form.view.html; // not sure why this is only available in init
  
      const group = $group && $group.length ? $group[ 0 ] : formHtml;
  
      widgets.forEach( Widget => {
          _instantiate( Widget, group );
      } );
  
      return true;
  }
docs: Initializes widgets
  
  @param  {jQuery} $group The element inside which the widgets have to be initialized.
  @param { *} options Options (e.g. helper function of Form.js passed)