build method
Implementation
CardForm build() {
_cardForm = CardFormCollector(
repository: _repository,
);
_configureField(_cardForm!, CardFieldType.cardNumber);
_configureField(_cardForm!, CardFieldType.cvv);
_configureField(_cardForm!, CardFieldType.cardHolderName);
_configureField(_cardForm!, CardFieldType.expiryMonth);
_configureField(_cardForm!, CardFieldType.expiryYear);
return CardForm(cardFormCollector: _cardForm!);
}