1. DomName('SVGLengthList.replaceItem')
  2. DocsEditable()
Length replaceItem(Length newItem, int index)

Source 

@DomName('SVGLengthList.replaceItem')
@DocsEditable()
Length replaceItem(Length newItem, int index) => _blink.BlinkSVGLengthList.instance.replaceItem_Callback_2_(this, newItem, index);