--- a/src/lte/model/epc-sgw-pgw-application.h	Thu Jun 01 16:57:22 2017 -0700
+++ b/src/lte/model/epc-sgw-pgw-application.h	Fri Jun 02 14:45:29 2017 +0200
@@ -47,6 +47,7 @@
  */
 class EpcSgwPgwApplication : public Application
 {
+  /// allow MemberEpcS11SapSgw<EpcSgwPgwApplication> class friend access
   friend class MemberEpcS11SapSgw<EpcSgwPgwApplication>;
 
 public: