+ The EVT_END_SESSION event is slightly different as it is sent by the system
+ when the user session is ending (e.g. because of log out or shutdown) and
+ so all windows are being forcefully closed. At least under MSW, after the
+ handler for this event is executed the program is simply killed by the
+ system. Because of this, the default handler for this event provided by
+ wxWidgets calls all the usual cleanup code (including wxApp::OnExit()) so
+ that it could still be executed and exit()s the process itself, without
+ waiting for being killed. If this behaviour is for some reason undesirable,
+ make sure that you define a handler for this event in your wxApp-derived
+ class and do not call @c event.Skip() in it (but be aware that the system
+ will still kill your application).
+