protected function mask($string)
 {
     return StringFilter::maskCreditCard($string);
 }
 public function testMaskCreditCardXmlEncoded()
 {
     $this->assertEquals('%3CcreditCardType%3EXX%3C%2FcreditCardType%3E', StringFilter::maskCreditCard('%3CcreditCardType%3ECA%3C%2FcreditCardType%3E'));
     $this->assertEquals('%3CcreditCardNumber%3EXXXXXXXXXXXXXXXX%3C%2FcreditCardNumber%3E', StringFilter::maskCreditCard('%3CcreditCardNumber%3E4564456445644564%3C%2FcreditCardNumber%3E'));
     $this->assertEquals('%3CcreditCardIdentifier%3EXXX%3C%2FcreditCardIdentifier%3E', StringFilter::maskCreditCard('%3CcreditCardIdentifier%3E123%3C%2FcreditCardIdentifier%3E'));
     $this->assertEquals('%3CcreditCardExpirationMonth%3EXX%3C%2FcreditCardExpirationMonth%3E', StringFilter::maskCreditCard('%3CcreditCardExpirationMonth%3E01%3C%2FcreditCardExpirationMonth%3E'));
     $this->assertEquals('%3CcreditCardExpirationYear%3EXX%3C%2FcreditCardExpirationYear%3E', StringFilter::maskCreditCard('%3CcreditCardExpirationYear%3E16%3C%2FcreditCardExpirationYear%3E'));
 }