Fixed typo. (#4179)

* Fixed typo.

Co-authored-by: Genevieve Warren <[email protected]>

Author: DavidKlempfner

xml/System.Threading/CancellationToken.xml

@@ -64,7 +64,7 @@
 ## Examples  
  The following example uses a random number generator to emulate a data collection application that reads 10 integral values from eleven different instruments. A value of zero indicates that the measurement has failed for one instrument, in which case the operation should be cancelled and no overall mean should be computed.  
   
- To handle the possible cancellation of the operation, the example instantiates a <xref:System.Threading.CancellationTokenSource> object that generates a cancellation token which is passed to a <xref:System.Threading.Tasks.TaskFactory> object. The <xref:System.Threading.Tasks.TaskFactory> object in turn passes the cancellation token to each of the tasks responsible for collecting readings for a particular instrument. The <xref:System.Threading.Tasks.TaskFactory.ContinueWhenAll%60%602%28System.Threading.Tasks.Task%7B%60%600%7D%5B%5D%2CSystem.Func%7BSystem.Threading.Tasks.Task%7B%60%600%7D%5B%5D%2C%60%601%7D%2CSystem.Threading.CancellationToken%29?displayProperty=nameWithType> method is called to ensure that the mean is computed only after all readings have been gathered successfully. If a task has not because it has been cancelled, the call to the <xref:System.Threading.Tasks.TaskFactory.ContinueWhenAll%2A?displayProperty=nameWithType> method throws an exception.  
+To handle the possible cancellation of the operation, the example instantiates a <xref:System.Threading.CancellationTokenSource> object that generates a cancellation token that's passed to a <xref:System.Threading.Tasks.TaskFactory> object. In turn, the <xref:System.Threading.Tasks.TaskFactory> object passes the cancellation token to each of the tasks responsible for collecting readings for a particular instrument. The <xref:System.Threading.Tasks.TaskFactory.ContinueWhenAll%60%602%28System.Threading.Tasks.Task%7B%60%600%7D%5B%5D%2CSystem.Func%7BSystem.Threading.Tasks.Task%7B%60%600%7D%5B%5D%2C%60%601%7D%2CSystem.Threading.CancellationToken%29?displayProperty=nameWithType> method is called to ensure that the mean is computed only after all readings have been gathered successfully. If a task has not completed because it was cancelled, the <xref:System.Threading.Tasks.TaskFactory.ContinueWhenAll%2A?displayProperty=nameWithType> method throws an exception.
   
  [!code-csharp[System.Threading.CancellationTokenSource.Class#1](~/samples/snippets/csharp/VS_Snippets_CLR_System/system.threading.cancellationtokensource.class/cs/cancel1.cs#1)]
  [!code-vb[System.Threading.CancellationTokenSource.Class#1](~/samples/snippets/visualbasic/VS_Snippets_CLR_System/system.threading.cancellationtokensource.class/vb/cancel1.vb#1)]