1. DomName('SVGTextContentElement.getSubStringLength')
  2. DocsEditable()
num getSubStringLength(int charnum, int nchars)

Source 

@DomName('SVGTextContentElement.getSubStringLength')
@DocsEditable()
num getSubStringLength(int charnum, int nchars) => _blink.BlinkSVGTextContentElement.instance.getSubStringLength_Callback_2_(this, charnum, nchars);