public function merge(array $public, array $private = []): Record
    {
        $public = array_merge($this->public, $public);
        $private = array_merge($this->private, $private);
        if ($this->isEditable()) {
            $this->public = $public;
            $this->private = $private;
            return $this;
        }
        return static::make($public, $this->isEditable(), $this->mutations, $this->private);
    }