KavenegarCall.getInstance().initCall(
  callId, accessToken, this,
  result => {
     call.setMediaStateChangedEventHandler
     (this::peerConnectionStateChanged);
     call.setMessagingStateChangedHandler
     (this::messagingSateChanged);
     call.onCallStateChanged(state =>
                             { Log.d("Call state is changed",state);});
	 call.onCallFinished(reason =>
                         { Log.d("Call state is changed",reason); });
	 call.onMediaStateChanged(event =>
                              { Log.d("Call state is changed",event); });
});