public function tableize(string $word) : string
    {
        $tableized = preg_replace('~(?<=\\w)([A-Z])~u', '_$1', $word);

        if ($tableized === null) {
            throw new RuntimeException(sprintf(
                'preg_replace returned null for value "%s"',
                $word
            ));
        }

        return mb_strtolower($tableized);
    }