points-index.go
func (points *PointsIndex) Range(topLeft Point, bottomRight Point) []Point {
	entries := points.index.Range(topLeft, bottomRight)
	accept := func(point Point) bool {
		return between(point.Lat(), bottomRight.Lat(), topLeft.Lat()) &&
			between(point.Lon(), topLeft.Lon(), bottomRight.Lon())
	}

	return getPoints(entries, accept)
}
func (points *PointsIndex) Range(topLeft Point, bottomRight Point) []Point {
	entries := points.index.Range(topLeft, bottomRight)
	accept := func(point Point) bool {
		return between(point.Lat(), bottomRight.Lat(), topLeft.Lat()) &&
			between(point.Lon(), topLeft.Lon(), bottomRight.Lon())
	}

	return getPoints(entries, accept)
}
// Range returns the points within the range defined by top left and bottom right.