internal void RaiseExecuting(CommandExecutionEventArgs e)
 {
     if (this.CommandExecuting != null)
     {
         this.CommandExecuting(this, e);
     }
 }
 internal void RaiseFinished(CommandExecutionEventArgs e)
 {
     if (this.CommandFinished != null)
     {
         this.CommandFinished(this, e);
     }
 }