1. @DomName('Document.createElement')
Element createElement(String tagName, [ String typeExtension ])

Source 

@DomName('Document.createElement')
Element createElement(String tagName, [String typeExtension]) {
  return (typeExtension == null)
      ? _blink.BlinkDocument.instance.createElement_Callback_1_(this, tagName)
      : _blink.BlinkDocument.instance
          .createElement_Callback_2_(this, tagName, typeExtension);
}