@Override
public <R extends HttpRequest> R bindToRequest(R request, Object input) {
checkArgument(input instanceof CreateSubscriptionRequest,
"this binder is only valid for CreateSubscriptionRequest!");
CreateSubscriptionRequest create = CreateSubscriptionRequest.class.cast(input);
JsonObject subscriptionObject = subscriptionRequestJsonObjectFunction.apply(create);
request.setPayload(subscriptionObject.toString());
request.getPayload().getContentMetadata().setContentType(MediaType.APPLICATION_JSON);
return request;