[pygtk] Point of __gproperties__ "default" argument?

[Jason Heeris]

Consider the class given in the "Sub-classing GObject" tutorial[1].
What is the point of the default value for 'fuel' on line 12? Given
that any access needs to go through the `do_get_property()` method
anyway, which will need to work out what to return from the state of
the object, I don't see how it could ever get used.

[1] http://www.pygtk.org/articles/subclassing-gobject/sub-classing-gobject-in-python.htm#d0e127

— Jason