I have a Glade file with some buttons and I use Gtk.Builder.connect_signals() to connect methods (on_button_toggled) with the corresponding signals (toggled). 
(It is acutally quickly which does that for me, but I can see and change that code, so that is only a detail).
What I want to do now, is stop a signal from being processed, e.g. though a call to object.handler_block(handler_id) or object.disconnect(handler_id). So my question is: how can I get the handler_ids for connections created via Gtk.Builder.connect_signals()? 
Normally you would get the handler_id from a call to one of: 
handler_id = object.connect(name, cb, cb_args)  
handler_id = object.connect_after(name, cb, cb_args)
handler_id = object.connect_object(name, cb, slot_object, cb_args)  
handler_id = object.connect_object_after(name, cb, slot_object, cb_args)
but the Gtk.Builder version does not return the ids.