geohash.go
func encodeInt(lat, lng float64) uint64 {
	latInt := encodeRange(lat, 90)
	lngInt := encodeRange(lng, 180)
	return interleave(latInt, lngInt)
}
func encodeInt(lat, lng float64) uint64 {
	latInt := encodeRange(lat, 90)
	lngInt := encodeRange(lng, 180)
	return interleave(latInt, lngInt)
}
// encodeInt provides a Go implementation of integer geohash. This is the
// default implementation of EncodeInt, but optimized versions are provided
// for certain architectures.