code: function zrange(key, start, end, withscores, req) {
    var val = this.getKey(key, req);
    if(val === undefined) return [];
    if(typeof withscores === 'object') {
      req = withscores;
      withscores = null;
    }
    return val.zrange(start, end, withscores);
  }
docs: Returns the specified range of elements in the sorted set.