1. @DomName('SVGTransformList.insertItemBefore')
  2. @DocsEditable()
Transform insertItemBefore(Transform newItem, int index)

Source 

@DomName('SVGTransformList.insertItemBefore')
@DocsEditable()
Transform insertItemBefore(Transform newItem, int index) =>
    _blink.BlinkSVGTransformList.instance
        .insertItemBefore_Callback_2_(this, newItem, index);