addItemToMap method
Implementation
Future<void> addItemToMap(String mapKey, String itemKey, dynamic value) async {
final _existingValue = getMap(mapKey);
_existingValue[itemKey] = value;
await setMap(mapKey, _existingValue);
}
Future<void> addItemToMap(String mapKey, String itemKey, dynamic value) async {
final _existingValue = getMap(mapKey);
_existingValue[itemKey] = value;
await setMap(mapKey, _existingValue);
}