1. DomName('CSSMediaRule.insertRule')
  2. DocsEditable()
int insertRule(String rule, int index)

Source 

@DomName('CSSMediaRule.insertRule')
@DocsEditable()
int insertRule(String rule, int index) => _blink.BlinkCSSMediaRule.instance.insertRule_Callback_2_(unwrap_jso(this), rule, index);