deleteTransaction method
Implementation
@override
Future<Map> deleteTransaction({required String idCheck}) async {
final sharedPreferences = await SharedPreferences.getInstance();
final data = sharedPreferences.getString(_keyCheckShared);
if (data == null) {
throw Exception('Empty');
}
final map = (jsonDecode(data) as Map);
map.removeWhere((key, value) => value['id'] == idCheck);
await sharedPreferences.setString(_keyCheckShared, jsonEncode(map));
return map;
}