code: public function ttl(bool $milliseconds = false): int
      {
          if ($milliseconds) {
              return $this->redis->pttl($this->key);
          }
  
          return $this->redis->ttl($this->key);
      }
docs: @param bool $milliseconds
  
  @return int TTL in (milli-) seconds, or a negative value in order to signal an error. To check, use
  self::RESPONSE_TTL_* constants.