dispose method

@override void dispose()

Implementation

@override
void dispose() {
  super.dispose();
  firstNameController.dispose();
  lastNameController.dispose();
  cardNumberController.dispose();
  expiryDateController.dispose();
  cvcController.dispose();
  zipController.dispose();
  // firstNameController.removeListener(dispose);
  cardNumberController.removeListener(getCardTypeFrmNumber);
}