probably a simple one, but cant get it to work;

i've changed the signature one on the methods to Task 

On my unit tests i am using fluent assertions.

but cant get this to work:

```
        _catalogVehicleMapper
            .Invoking(m => m.MapToCatalogVehiclesAsync(searchResult, filtersInfo, request, default(CancellationToken)))
            .Should().Throw<ArgumentException>()
            .WithMessage("One of passed arguments has null value in mapping path and can not be mapped");

```

the `MapToCatalogVehiclesAsync` is the async method, but i need to await it, but awaiting and asyncing the invocation, doesnt seem to do it..
someone..?