public static void ProcessData(Connection conn, DataTransfer transfer)
        {
            if (conn == null || transfer == null)
            {
                return;
            }

            if (transfer is AuthenticationRequest)
            {
                AuthenticationRequest authenticationRequest = (AuthenticationRequest)transfer;
                PlayerAccount         player         = new PlayerAccount(authenticationRequest.Username, authenticationRequest.Password);
                string authenticationResponseMessage = AccountFileHandler.ReadAccount(player);

                if (authenticationResponseMessage == null)
                {
                    PlayerHandler.AddPlayer(player);
                }

                conn.SendData(new AuthenticationResponse(authenticationResponseMessage));
            }
        }
        public static void Shutdown()
        {
            if (online)
            {
                connectionHandler.Reset();
                ConnectionsRepository.Reset();

                foreach (PlayerAccount account in PlayerHandler.GetPlayers())
                {
                    AccountFileHandler.SaveAccount(account);
                }

                listener.Stop();
                thread.Abort();

                Console.WriteLine("Server has shut down.");
            }
            else
            {
                Console.WriteLine("Failed since the server isn't online.");
            }
        }