SEBA-457 Core xproto cleanup

Change-Id: Ib99680dd81016694094a5c230afdf9dcf2cb307e
diff --git a/lib/xos-genx/xosgenx/targets/mock_classes.xtarget b/lib/xos-genx/xosgenx/targets/mock_classes.xtarget
index 61c2f1f..bc56747 100644
--- a/lib/xos-genx/xosgenx/targets/mock_classes.xtarget
+++ b/lib/xos-genx/xosgenx/targets/mock_classes.xtarget
@@ -225,6 +225,9 @@
 
 model_accessor = ModelAccessor()
 
+def get_first_site():
+    return model_accessor.Site.objects.first().id
+
 class ObjectSet(object):
     def __init__(self, objects):
         self.objects = objects