code: function(geohash) {
    var error;
  
    if (typeof geohash !== "string") {
      error = "geohash must be a string";
    }
    else if (geohash.length === 0) {
      error = "geohash cannot be the empty string";
    }
    else {
      for (var i = 0, length = geohash.length; i < length; ++i) {
        if (g_BASE32.indexOf(geohash[i]) === -1) {
          error = "geohash cannot contain \"" + geohash[i] + "\"";
        }
      }
    }
  
    if (typeof error !== "undefined") {
      throw new Error("Invalid WildGeo geohash '" + geohash + "': " + error);
    }
  }
docs: Validates the inputted geohash and throws an error if it is invalid.
  校验输入的geohash值，不合法则抛出错误
  @param {string} geohash 被校验的geohash值.