TextTrack addTextTrack(
String kind,
[String label,
String language]
)

Not documented.

Source

TextTrack addTextTrack(String kind, [String label, String language]) {
  if (language != null) {
    return wrap_jso(_blink.BlinkHTMLMediaElement.instance.addTextTrack_Callback_3_(unwrap_jso(this), kind, label, language));
  }
  if (label != null) {
    return wrap_jso(_blink.BlinkHTMLMediaElement.instance.addTextTrack_Callback_2_(unwrap_jso(this), kind, label));
  }
  return wrap_jso(_blink.BlinkHTMLMediaElement.instance.addTextTrack_Callback_1_(unwrap_jso(this), kind));
}