using BeginVerifyPin and EndVerifyPin methods in a UCMA workflow

need a simple example of how to call ApplicationPinServices BeginVeri开发者_开发百科fyPin and EndVerifyPin methods from inside a UCMA workflow to verify user pin number... ApplicationPinServices has an internal constructor and i can't find a way to instantiate it in order to call the methods.

I was able to verify the pin by casting the conversation endpoint to ApplicationEndpoint which contains a reference to PinServices Class:

var localEndPoint = this.communicationsSequenceActivity1.CallProvider.Call.Conversation.Endpoint as ApplicationEndpoint;

PinVerificationResult result = localEndPoint.PinServices.EndVerifyPin
                                     (localEndPoint.PinServices.BeginVerifyPin(
                                                        userSIP, selectedPin, null, null, null));