<PackageReference Include="System.Reactive" Version="4.3.2" />

ConcurrencyAbstractionLayerImpl

public bool SupportsLongRunning { get; }

public IDisposable QueueUserWorkItem(Action<object> action, object state)

public void Sleep(TimeSpan timeout)

public void StartThread(Action<object> action, object state)

public IDisposable StartTimer(Action<object> action, object state, TimeSpan dueTime)