Returning Nothing from a non-Async Task/Task(Of TResult) procedure will cause a
NullReferenceException at runtime if the procedure is awaited. This problem can be avoided by returning Task.CompletedTask or Task.FromResult(Of TResult)(Nothing)
respectively.
Public Function DoFooAsync() As Task
Return Nothing ' Noncompliant: Causes a NullReferenceException if awaited.
End Function
Public Async Function Main() As Task
Await DoFooAsync() ' NullReferenceException
End Function
