code: public function insert($value, $pivot, bool $after = true): int
      {
          return $this->redis->linsert($this->key, $after, $this->serialize($pivot), $this->serialize($value));
      }
docs: @param mixed $value Serialized and inserted after or before $pivot.
  @param mixed $pivot The $pivot item to select.
  @param bool  $after Whether the $value shall be inserted before or after $pivot.
  
  @return int Length of list after insertion. Negative in case of failure. Use RESPONSE_INSERT_* constants to
  check for which error.