Constants_Linq
public const string USE_ASYNC = "This blocking operation is no longer supported. Instead, use the async version in combination with C# and Visual Basic async/await support. In case you need a blocking operation, use Wait or convert the resulting observable sequence to a Task object and block."
public const string USE_TASK_FROMASYNCPATTERN = "This conversion is no longer supported. Replace use of the Begin/End asynchronous method pair with a new Task-based async method, and convert the result using ToObservable. If no Task-based async method is available, use Task.Factory.FromAsync to obtain a Task object."