If the CardBrand has variants, and the cardNumber starts with one of the variant prefixes, return the length for that variant. Otherwise, return defaultMaxLength.

isMaxCvc

fun isMaxCvc(cvcText: String?): Boolean

isValidCardNumberLength

fun isValidCardNumberLength(cardNumber: String?): Boolean

Checks to see whether the input number is of the correct length, given the assumed brand of the card. This function does not perform a Luhn check.

isValidCvc

fun isValidCvc(cvc: String): Boolean