code: 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
  }
docs: // Round returns a point inside the box, making an effort to round to minimal
  // precision.