@property
    def extent(self):
        env = self.envelope
        if isinstance(env, Point):
            xmin, ymin = env.tuple
            xmax, ymax = xmin, ymin
        else:
            xmin, ymin = env[0][0]
            xmax, ymax = env[0][2]
        return (xmin, ymin, xmax, ymax)
Returns a tuple representing the SQL elements in the "group by" clause.
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.2/django/contrib/gis/geos/geometry.py/GEOSGeometry.extent--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.2/django/db/models/sql/compiler.py/SQLCompiler.get_grouping