Moq Issue when trying Mock EventStore Method

[no1melman]

I get this annoying error when trying to mock the event store...

EventStore/tests/AspNetCore/StreamSubscriberTests.fs

Lines 67 to 82 in e80c5e8

	// Get error here... bugger
	// Non-overridable members (here: EventStoreClient.SubscribeToStreamAsync) may not be used in setup / verification expr
	mockClient.Setup(fun x -> x.SubscribeToStreamAsync(
	"Test Stream",
	It.IsAny<Func<StreamSubscription, ResolvedEvent, CancellationToken, Task>>(),
	resolveLinkTos = false,
	subscriptionDropped = It.IsAny<Action<StreamSubscription, SubscriptionDroppedReason, exn>>(),
	configureOperationOptions = It.IsAny<Action<EventStoreClientOperationOptions>>(),
	userCredentials = It.IsAny<UserCredentials>(),
	cancellationToken = It.IsAny<CancellationToken>()))
	.Callback<string, Func<StreamSubscription, ResolvedEvent, CancellationToken, Task>>((fun n evAppeared ->
	let toFire = task {
	do! releaseTrigger.WaitAsync() // this will wait for the subscription to be created below
	evAppeared.Invoke(null, reco, cts.Token) |> ignore
	}
	()))

Non-overridable members (here: EventStoreClient.SubscribeToStreamAsync) may not be used in setup / verification expr