let main window =
GAction.add_actions window#actions
[ GAction.add_action
"CallGraph" ~label:"_Show Call Graph" ~callback:show_graph_win];
ignore
(window#ui_manager#add_ui_from_string
"<ui><menubar name='MenuBar'>
<menu action='ViewMenu'>
<menuitem action='CallGraph'/>
</menu>
</menubar>
</ui>")