geometry(obj)
Takes the object returned by get_object() and returns the feed’s geometry. Typically this is a GEOSGeometry instance, or can be a tuple to represent a point or a box. For example:
class ZipcodeFeed(Feed):
def geometry(self, obj):
# Can also return: `obj.poly`, and `obj.poly.centroid`.
return obj.poly.extent # tuple like: (X0, Y0, X1, Y1).