converting drawable to pixbuf

[Zoltán Vörös <zvoros gmail com>]

Hi All,

I am trying to add a number of drawables to a treeview, and I believe I 
could attach only pixbuffers. Now, my question is how can one convert 
drawables into pixbufs? In pygtk there used to be a function that did 
that, but I couldn't find anything for pygi.
Could anyone suggest a viable solution to the problem above?
Thanks,
Zoltán