IsoCodes\ZipCode::getAvailableCountries PHP Метод

    public static function getAvailableCountries()
    {
        return array_keys(self::$patterns);
    }

 public function testGetAvailableCountries()
 {
     $countries = ZipCode::getAvailableCountries();
     $this->assertTrue(is_array($countries));
     $this->assertContains('FR', $countries);
     $this->assertContains('US', $countries);
 }