pin method
Saves item to value storage
Implementation
Future<bool> pin() async {
if (objectId != null) {
await unpin();
final Map<String, dynamic>? objectMap = parseEncode(this, full: true);
final String json = jsonEncode(objectMap);
await ParseCoreData().getStore().setString(objectId!, json);
return true;
} else {
return false;
}
}