Index: sources/canbus/messagehandler.h
===================================================================
diff -u -r9a3ee027dbc33f39ee7df2a9dc5a7897c6b1854d -rf623529d6ec25b555f3ac2248d71fc2b5e7063d6
--- sources/canbus/messagehandler.h	(.../messagehandler.h)	(revision 9a3ee027dbc33f39ee7df2a9dc5a7897c6b1854d)
+++ sources/canbus/messagehandler.h	(.../messagehandler.h)	(revision f623529d6ec25b555f3ac2248d71fc2b5e7063d6)
@@ -28,6 +28,9 @@
 // Define
 #define _MessageHandler MessageHandler::I()
 
+// forward declarations
+class unittests;
+
 // namespace
 using namespace Gui;
 namespace Can {
@@ -39,7 +42,21 @@
 {
     Q_OBJECT
 
-SINGLETON_DECL(MessageHandler)
+    // friends
+    friend class ::unittests;
+
+    // constants
+    enum payload_info {
+        ePayload_Sync = 0xA5,
+    };
+
+    enum can_id {
+        eChlid_HD = 0x020,
+        eChlid_UI = 0x100,
+    };
+
+    // Singleton
+    SINGLETON_DECL(MessageHandler)
 public:
     void init();