/// <summary>
/// Does the work asynchronously - protected implementation.
/// </summary>
/// <typeparam name="TResult">The type of the result.</typeparam>
/// <param name="workItem">The work item.</param>
/// <param name="cancellationToken">The cancellation token.</param>
/// <returns>
/// An awaitable task, result is TResult.
/// </returns>
protected override Task <TResult> DoWorkInternalAsync <TResult>(
IWorkItem <TResult> workItem,
CancellationToken cancellationToken)
{
return(workItem.DoWorkAsync(cancellationToken));
}