private void CheckForClients()
        {
            List <Client> tempClients = _persistable.GetClients();

            bool newClientsInDatabase = !(tempClients.Count == _clients.Count || tempClients.All(_clients.Contains));

            if (newClientsInDatabase)
            {
                _clients = tempClients;
                ClientsUpdatedEventHandler?.Invoke(_clients, EventArgs.Empty);
            }
        }
        private ClientRepo(IPersistable persistable)
        {
            _persistable = persistable;

            _clients = _persistable.GetClients();
        }