Beijing geohash: wx4g0bm
precision: 7
center near Beijing: true
bbox: 39.903717041015625,116.40701293945312,39.90509033203125,116.40838623046875
north: wx4g0bt
south: wx4g0bj
east: wx4g0bq
west: wx4g0bk
geohash example: PASS
