public static function increment(string $string, int $start = 1, string $separator = '_'): string
	{
		preg_match('/(.+)' . preg_quote($separator) . '([0-9]+)$/', $string, $matches);

		return isset($matches[2]) ? $matches[1] . $separator . ((int) $matches[2] + 1) : $string . $separator . $start;
	}