Index: sources/model/hd/data/MTreatmentOutletFlowData.h
===================================================================
diff -u -r3aab84456cfbdc4c4f495975ba9b8968eb844309 -raa0772fe1b0ff6b07e9f64e8c38acad66ad5468d
--- sources/model/hd/data/MTreatmentOutletFlowData.h	(.../MTreatmentOutletFlowData.h)	(revision 3aab84456cfbdc4c4f495975ba9b8968eb844309)
+++ sources/model/hd/data/MTreatmentOutletFlowData.h	(.../MTreatmentOutletFlowData.h)	(revision aa0772fe1b0ff6b07e9f64e8c38acad66ad5468d)
@@ -20,10 +20,16 @@
 #include "MAbstract.h"
 #include "types.h"
 
+// forward declarations
+class tst_models;
+
 namespace Model {
 
 class MOutletFlow : public MAbstract {
 
+    // friends
+    friend class ::tst_models;
+
     QVariantList parameters() const override;
 
     struct {