processString method
Processes the given text to extract credit card information.
Returns a CreditCardModel containing the extracted information, or null if not all required information is found.
Implementation
CreditCardModel? processString(String text) {
// Check for expiration date
processDate(text);
// Check for card number
processNumber(text);
// Check for cardholder's name
processName(text);
return getCreditCardModel();
}