toJson method
Converts the response to JSON.
Implementation
String toJson() {
final Map<String, dynamic> json = {
'success': success,
};
if (data != null) json['data'] = data;
if (error != null) json['error'] = error;
if (message != null) json['message'] = message;
if (statusCode != null) json['status_code'] = statusCode;
return jsonEncode(json);
}