1. DomName('CSSKeyframesRule.insertRule')
  2. DocsEditable()
  3. Experimental()
void appendRule(String rule)

Source 

@DomName('CSSKeyframesRule.insertRule')
@DocsEditable()
@Experimental() // untriaged
void appendRule(String rule) => _blink.BlinkCSSKeyframesRule.instance.insertRule_Callback_1_(unwrap_jso(this), rule);