//====== public methods
public void StartGame(IGraphNode mainNode)
{
logger.Log($"Starting game.", false);
IGraphNode node = mainNode;
ScreenTransitionActivator nextTransition = null;
do
{
GameModule module = node.GetInstance();
logger.Log("Going to module: " + module.GetType().Name, false);
var loop = new GameModuleLoop(module, nextTransition ?? NullTransition.Activator, hal, sleeper);
var result = loop.Start();
(node, nextTransition) = node.GetNextNode(result);
}while (node is not null);
logger.Log($"Exiting game.", false);
}