func (client *SIRIClient) VehicleMonitoringSubscription(request *siri.SIRIVehicleMonitoringSubscriptionRequest) (*sxml.XMLSubscriptionResponse, error) {
    node, err := client.prepareAndSendRequest(siriClientArguments{
        request:           request,
        requestType:       SUBSCRIPTION,
        expectedResponses: []string{"SubscribeResponse", "SubscriptionResponse"},