Location of bookmark-popup-menu in code files

[Selspam <selspam posteo de>]

Dear all,

I've been browsing through the code trying to find a way to patch 
nautilus in such a way that I can remove the default-bookmarks (withou 
modifying my xdg-files in the home directory). Changing 
'nautilus_bookmark_get_is_builtin' in bookmark.c to return always False 
didn't help, so I wanted to take a look at the popup-menu directly. Does 
anyone know where to find it?

Thank you and kind regard,
Selspam

(PS: I was playing around with the 3.30.5 version (Debian...), so if 
this feature is already somehow implemented and I just don't know about 
it, sorry.)