code: function enable( group ) {
      widgets.forEach( Widget => {
          const els = _getElements( group, Widget.selector )
              .filter( el => el.nodeName.toLowerCase() === 'select' ? !el.getAttribute( 'readonly' ) : !el.readOnly );
          new Collection( els ).enable( Widget );
      } );
  }
docs: Enables widgets if they weren't enabled already if they are not readonly.
  In most widgets, this function will do nothing because the disabled attribute was automatically removed from all
  fieldsets, inputs, textareas and selects inside the branch element provided as parameter.
  Note that this function can be called before the widgets have been initialized and will in that case do nothing. This is
  actually preferable than waiting for create() to complete, because enable() will never do anything that isn't
  done during create().
  
  @param  {Element} group [description]