#vulnerable code 
                                public static void main(String[] args) throws Exception {
        TokenManager tokenManager = new TokenManager(new ConcurrentHashMap<>(), null, null, "");
        String email = "dmitriy@blynk.cc";
        String pass = "b";
        String appName = AppName.BLYNK;
        User user = new User(email, SHA256Util.makeHash(pass, email), appName, "local", false, false);
        user.purchaseEnergy(98000);

        int count = 300;

        user.profile.dashBoards = new DashBoard[count];
        for (int i = 1; i <= count; i++) {
            DashBoard dash = new DashBoard();
            dash.id = i;
            dash.theme = Theme.Blynk;
            dash.isActive = true;
            user.profile.dashBoards[i - 1] = dash;
        }

        List<String> tokens = new ArrayList<>();
        for (int i = 1; i <= count; i++) {
            tokens.add(tokenManager.refreshToken(user, i, 0));
        }

        write("/path/300_tokens.txt", tokens);

        write(Paths.get("/path/" + email + "." + appName + ".user"), JsonParser.toJson(user));

        //scp /path/dmitriy@blynk.cc.Blynk.user root@IP:/root/data/

    } 
                            #location 22 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                public static void main(String[] args) throws Exception {
        TokenManager tokenManager = new TokenManager(new ConcurrentHashMap<>(), null, null, "");
        String email = "dmitriy@blynk.cc";
        String pass = "b";
        String appName = AppName.BLYNK;
        User user = new User(email, SHA256Util.makeHash(pass, email), appName, "local", false, false);
        user.purchaseEnergy(98000);

        int count = 300;

        user.profile.dashBoards = new DashBoard[count];
        for (int i = 1; i <= count; i++) {
            DashBoard dash = new DashBoard();
            dash.id = i;
            dash.theme = Theme.Blynk;
            dash.isActive = true;
            user.profile.dashBoards[i - 1] = dash;
        }

        List<String> tokens = new ArrayList<>();
        for (int i = 1; i <= count; i++) {
            //tokens.add(tokenManager.refreshToken(user, i, 0));
        }

        write("/path/300_tokens.txt", tokens);

        write(Paths.get("/path/" + email + "." + appName + ".user"), JsonParser.toJson(user));

        //scp /path/dmitriy@blynk.cc.Blynk.user root@IP:/root/data/

    }