func (b Box) Round() (lat, lng float64) {
	x := maxDecimalPower(b.MaxLat - b.MinLat)
	lat = math.Ceil(b.MinLat/x) * x
	x = maxDecimalPower(b.MaxLng - b.MinLng)
	lng = math.Ceil(b.MinLng/x) * x
	return
}
func (b Box) Round() (lat, lng float64) {
	x := maxDecimalPower(b.MaxLat - b.MinLat)
	lat = math.Ceil(b.MinLat/x) * x
	x = maxDecimalPower(b.MaxLng - b.MinLng)
	lng = math.Ceil(b.MinLng/x) * x
	return
}
// Round returns a point inside the box, making an effort to round to minimal
// precision.