This property enables a consumer to access the System.Threading.Tasks.Task`1 that is controlled by this instance. When you create a System.Threading.Tasks.TaskCompletionSource`1 object, the Task.Status property of this System.Threading.Tasks.Task`1 object returns TaskStatus.WaitingForActivation

The TaskCompletionSource`1.SetResult(`0), TaskCompletionSource`1.SetException(Exception), TaskCompletionSource`1.SetException(IEnumerable<Exception>), and TaskCompletionSource`1.SetCanceled methods (and their "Try" variants) on this instance all result in the relevant state transitions on this underlying Task.