anchor.diff:  
     // Platform messages are asynchronous, so we initialize in an async method.
     initPlatformState() async {
  -    String platformVersion;
  +    String platformVersion = '';
  +    /*final Map<String, dynamic> mediaConstraints = {
  +      "audio": true,
  +      "video": {
  +        "mandatory": {
  +          "minWidth": 640, // Provide your own width, height and frame rate here
  +          "minHeight": 360,
  +          "minFrameRate": 30,
  +        },
  +        "facingMode": "user",
  +        "optional": [],
  +      }
  +    };*/
  +    final Map<String, dynamic> mediaConstraints = {
  +      "audio": true,
  +      "video": false,
  +    };
  +    const configuration = {"iceServers": [{"url": "stun:stun.l.google.com:19302"}]};
       // Platform messages may fail, so we use a try/catch PlatformException.
       try {
  -      platformVersion = await Webrtc.platformVersion;
  -    } on PlatformException {
  +      _localStream = await getUserMedia(mediaConstraints);
  +      platformVersion = _localStream.streamId();
  +    } catch(e) {
         platformVersion = 'Failed to get platform version.';
       }
   
  
positive.code:           title: new Text('Plugin example app'),
          ),
          body: new Center(
            child: new Text('Running on: $_platformVersion\n'),
          ),
        ),
      );
  
negative.code:       return;
  
      setState(() {
        _version = platformVersion;
      });
    }
  
  