toJson method
Implementation
Map<String, String> toJson() {
// only push to the Map if the value is not null
return <String, String>{
'req_id': req_id,
'client_id': client_id,
'amount': amount.toString(),
'description': description,
'notification_url': notification_url,
'expiry': expiry.toString(),
'email': email ?? '',
'contact': contact ?? '',
'name': name ?? '',
'redirect_url': redirect_url ?? '',
'param1': param1 ?? '',
'param2': param2 ?? '',
};
}