/// <summary>
 /// An event handler called when an asynchronous request for a PlanetLab resource was canceled.
 /// </summary>
 /// <param name="state">The request state.</param>
 protected virtual void OnRequestCanceled(RequestState state)
 {
     // If the request state is not null.
     if (null != state)
     {
         // If the delegate for this method is not null.
         if (null != state.ActionRequestCanceled)
         {
             // Call the delegate.
             state.ActionRequestCanceled(state);
         }
     }
 }