public int ValidateGraph(ILogger l)
 {
     FunctionGraphValidationMessageLogger.Mode = FunctionGraphValidationMessageLogger.LoggerMode.NotificationNoCollect;
     FunctionGraphValidationMessageLogger.RegisterForMessageNotifications((m) => m.Log(l));
     if (RootNode == null)
     {
         FunctionGraphValidationMessageLogger.LogError("No Root Node defined!");
         return(1);
     }
     return(RootNode.Validate());
 }