docs: function hincrbyfloat(key, field, amount, req) {
    var map = this.getKey(key, req)
      , val;
    if(!map) {
      map = new HashMap();
      this.setKey(key, map, undefined, undefined, undefined, req);
    }
    val = utils.strtofloat(map.getKey(field));
    amount = utils.strtofloat(amount);
    val += amount;
    map.setKey(field, val);
    // store as number and return a number,
    // the command implementation should coerce the result
    // to a string for a bulk string reply
    return val;
  }