///-------------------------------------------------------------------------------------------------
 /// <summary>
 ///  When overridden in a derived class, responds to the notification that an operation has
 ///  started.
 /// </summary>
 ///-------------------------------------------------------------------------------------------------
 public override void OperationStarted()
 {
     if (OldContext != null)
     {
         OldContext.OperationStarted();
     }
     else
     {
         base.OperationStarted();
     }
 }