toJson method
Implementation
Map<String, dynamic> toJson() {
final map = <String, dynamic>{};
if (_l1 != null) {
map['l1'] = _l1?.toJson();
}
if (_l2 != null) {
map['l2'] = _l2?.toJson();
}
if (_l3 != null) {
map['l3'] = _l3?.toJson();
}
return map;
}