IsoCodes\Bban::validate PHP Метод

    public static function validate($bban)
    {
        if (mb_strlen($bban) !== 23) {
            return false;
        }
        $key = substr($bban, -2);
        $bank = substr($bban, 0, 5);
        $branch = substr($bban, 5, 5);
        $account = substr($bban, 10, 11);
        $account = strtr($account, 'ABCDEFGHIJKLMNOPQRSTUVWXYZ', '12345678912345678923456789');
        return 97 - bcmod(89 * $bank + 15 * $branch + 3 * $account, 97) === (int) $key;
    }

 /**
  * testInvalidBban
  *
  * @param mixed $bban
  *
  * @dataProvider getInvalidBbans
  *
  * @return void
  */
 public function testInvalidBban($bban)
 {
     $this->assertFalse(Bban::validate($bban));
 }