Inheritance: Message, IObjectReference
 void IMessageVisitor.Visit(StartSessionTimeCountdownMessage message)
 {
 }
 /// <inheritdoc/>
 public virtual void Visit(StartSessionTimeCountdownMessage message)
 {
 }
 /// <inheritdoc/>
 public override void Visit(StartSessionTimeCountdownMessage message)
 {
     Model.OnSessionTimeCountDownStarted();
 }