toJson method
Implementation
Map<String, dynamic> toJson() => {
'bin': bin,
if (status != null) 'status': status,
if (token != null) 'token': token,
'expiry_year': expiryYear,
'expiry_month': expiryMonth,
'transaction_reference': transactionReference,
'type': type,
'number': number,
'origin': origin,
};