public static function isLegacy (array $parts = null)
	{
		if ($parts === null)
			return false;

		$keys = PartsLegacy::$legacyKeys;

		unset($keys[array_search('country', $keys)]);

		foreach ($keys as $key)
			if (isset($parts[$key]) || array_key_exists($key, $parts))
				return true;

		return false;
	}