<PackageReference Include="System.ComponentModel.EventBasedAsync" Version="4.0.11-beta-23409" />

System.ComponentModel.AsyncOperation

public sealed class AsyncOperation
Tracks the lifetime of an asynchronous operation.
public SynchronizationContext SynchronizationContext { get; }

Gets the SynchronizationContext object that was passed to the constructor.

public object UserSuppliedState { get; }

Gets or sets an object used to uniquely identify an asynchronous operation.

public void OperationCompleted()

Ends the lifetime of an asynchronous operation.

public void Post(SendOrPostCallback d, object arg)

Invokes a delegate on the thread or context appropriate for the application model.

public void PostOperationCompleted(SendOrPostCallback d, object arg)

Ends the lifetime of an asynchronous operation.