class RawDbCollection {
String collectionName;
Future<Map> findOne([selector]) { throw new Exception('method findOne must be implemented'); }
Future<int> count([selector]) { throw new Exception('method count must be implemented'); }
Future<List<Map>> find([selector]) { throw new Exception('method find must be implemented'); }
Future remove([selector]) { throw new Exception('method find must be implemented');}
}