title: When does Task.Run(Action, CancellationToken) throw TaskCanceledException?
body: <p>According to <a href="http://msdn.microsoft.com/en-us/library/hh160373(v=vs.110).aspx" rel="noreferrer">documentation</a> <code>Task.Run(Action, CancellationToken)</code> throws <code>TaskCanceledException</code> when the task has been canceled.</p>
  
  <p>When exactly does <code>Task.Run(Action, CancellationToken)</code> throw <code>TaskCanceledException</code>? It is not clear what conditions must be met for this exception to be thrown.</p>