<PackageReference Include="Microsoft.Bcl" Version="1.1.7" />

System.Threading.Tasks.TaskExtensions

public static class TaskExtensions
Provides a set of static (Shared in Visual Basic) methods for working with specific kinds of Task instances.
public static Task Unwrap(this Task<Task> task)

Creates a proxy TaskTask that represents the asynchronous operation of a Task{Task}.

public static Task<TResult> Unwrap<TResult>(this Task<Task<TResult>> task)

Creates a proxy Task<T>Task{TResult} that represents the asynchronous operation of a Task{Task{TResult}}.