1. DomName('SVGPathSegList.replaceItem')
  2. DocsEditable()
PathSeg replaceItem(PathSeg newItem, int index)

Source 

@DomName('SVGPathSegList.replaceItem')
@DocsEditable()
PathSeg replaceItem(PathSeg newItem, int index) => wrap_jso(_blink.BlinkSVGPathSegList.instance.replaceItem_Callback_2_(unwrap_jso(this), unwrap_jso(newItem), index));