private void Handle(SystemMessage.SystemCoreReady message)
 {
     if (_subSystems == null || _subSystems.Length == 0)
     {
         _outputBus.Publish(new SystemMessage.SystemReady());
     }
     else
     {
         _outputBus.Publish(message);
     }
 }
 public void Handle(SystemMessage.SystemCoreReady message)
 {
     _systemReady = true;
     StartWhenConditionsAreMet();
 }