When to free GtkBuilder

[Tristian Celestin <tristian celestin outlook com>]

Is it necessary to keep a GtkBuilder object around once I've obtained 
references to relevant widgets and connected the widgets to handlers? 
Lots of code I've seen doesn't free the builder after it's been 
instantiated, such as in this example: 
https://github.com/chergert/custom-gtk-widgets/blob/master/eggpanel/main.c