Creates a System.Threading.Tasks.Task that executes an end method action when a specified IAsyncResult completes.
A System.Threading.Tasks.Task that represents the asynchronous operation.
The erload:System.Threading.Tasks.TaskFactory.FromAsync overloads that take an asyncResult parameter are not as efficient as the overloads that take a beginMethod parameter. If performance is an issue, use the overloads that provide the beginMethod/endMethod pattern.