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

System.ComponentModel.AsyncOperationManager

public static class AsyncOperationManager
Provides concurrency management for classes that support asynchronous method calls. This class cannot be inherited.
public static SynchronizationContext SynchronizationContext { get; set; }

Gets or sets the synchronization context for the asynchronous operation.

public static AsyncOperation CreateOperation(object userSuppliedState)

Returns an AsyncOperation for tracking the duration of a particular asynchronous operation.