// Import package
    import 'package:headset_connection_event/headset_event.dart';

    // Instantiate it
    HeadsetEvent headsetPlugin = new HeadsetEvent();
    HeadsetState headsetEvent;

    /// if headset is plugged
    headsetPlugin.getCurrentState.then((_val){
      setState(() {
        headsetEvent = _val;
      });
    });

    /// Detect the moment headset is plugged or unplugged
    headsetPlugin.setListener((_val) {
      setState(() {
        headsetEvent = _val;
      });
    });