void addFromUri(String src, [ num weight ])

Source 

void addFromUri(String src, [num weight]) {
  if (weight != null) {
    _blink.BlinkSpeechGrammarList.instance.addFromUri_Callback_2_(this, src, weight);
    return;
  }
  _blink.BlinkSpeechGrammarList.instance.addFromUri_Callback_1_(this, src);
  return;
}