''

def save(self, out, format):

    if (format == 'MVT'):
        mvt.encode(out, [])
    elif (format == 'JSON'):
        geojson.encode(out, [], 0, False)
    elif (format == 'TopoJSON'):
        ll = SphericalMercator().projLocation(Point(*self.bounds[0:2]))
        ur = SphericalMercator().projLocation(Point(*self.bounds[2:4]))
        topojson.encode(out, [], (ll.lon, ll.lat, ur.lon, ur.lat), False)
    elif (format == 'PBF'):
        pbf.encode(out, [], None, self.bounds)
    else:
        raise ValueError(format)
