1. @DomName('ConsoleBase.warn')
  2. @DocsEditable()
  3. @Experimental()
void warn(Object arg)

Source 

@DomName('ConsoleBase.warn')
@DocsEditable()
@Experimental() // untriaged
void warn(Object arg) =>
    _blink.BlinkConsoleBase.instance.warn_Callback_1_(this, arg);