class FakeRedis::GeoSet::Point

def haversine_distance(lat1, lon1, lat2, lon2)
  h = Math.sin((lat2 - lat1) / 2) ** 2 + Math.cos(lat1) * Math.cos(lat2) *
        Math.sin((lon2 - lon1) / 2) ** 2
  2 * EARTH_RADIUS_IN_M * Math.asin(Math.sqrt(h))
end