#vulnerable code 
                                @Override
    public boolean execute(CommandSender sender, String currentAlias, String[] args) {
        if (!testPermission(sender)) return true;
        if (args.length < 1 || args.length > 4) {
            sender.sendMessage(ChatColor.RED + "Usage: " + usageMessage);
            return false;
        }

        Player player;

        if (args.length == 1 || args.length == 3) {
            if (sender instanceof Player) {
                player = (Player) sender;
            } else {
                sender.sendMessage("Please provide a player!");
                return true;
            }
        } else {
            player = Bukkit.getPlayerExact(args[0]);
        }

        if (player == null) {
            sender.sendMessage("Player not found: " + args[0]);
        }

        if (args.length < 3) {
            Player target = Bukkit.getPlayerExact(args[args.length - 1]);
            if (target == null) {
                sender.sendMessage("Can't find user " + args[args.length - 1] + ". No tp.");
            }
            player.teleport(target, TeleportCause.COMMAND);
            sender.sendMessage("Teleported " + player.getName() + " to " + target.getName());
        } else if (player.getWorld() != null) {
            int x = getInteger(sender, args[args.length - 3], -30000000, 30000000);
            int y = getInteger(sender, args[args.length - 2], 0, 256);
            int z = getInteger(sender, args[args.length - 1], -30000000, 30000000);

            Location location = new Location(player.getWorld(), x, y, z);
            player.teleport(location);
            sender.sendMessage("Teleported " + player.getName() + " to " + x + "," + y + "," + z);
        }
        return true;
    } 
                            #location 32 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @Override
    public boolean execute(CommandSender sender, String currentAlias, String[] args) {
        if (!testPermission(sender)) return true;
        if (args.length < 1 || args.length > 4) {
            sender.sendMessage(ChatColor.RED + "Usage: " + usageMessage);
            return false;
        }

        Player player;

        if (args.length == 1 || args.length == 3) {
            if (sender instanceof Player) {
                player = (Player) sender;
            } else {
                sender.sendMessage("Please provide a player!");
                return true;
            }
        } else {
            player = Bukkit.getPlayerExact(args[0]);
        }

        if (player == null) {
            sender.sendMessage("Player not found: " + args[0]);
            return true;
        }

        if (args.length < 3) {
            Player target = Bukkit.getPlayerExact(args[args.length - 1]);
            if (target == null) {
                sender.sendMessage("Can't find user " + args[args.length - 1] + ". No tp.");
                return true;
            }
            player.teleport(target, TeleportCause.COMMAND);
            Command.broadcastCommandMessage(sender, "Teleported " + player.getName() + " to " + target.getName());
        } else if (player.getWorld() != null) {
            int x = getInteger(sender, args[args.length - 3], -30000000, 30000000);
            int y = getInteger(sender, args[args.length - 2], 0, 256);
            int z = getInteger(sender, args[args.length - 1], -30000000, 30000000);

            Location location = new Location(player.getWorld(), x, y, z);
            player.teleport(location);
            Command.broadcastCommandMessage(sender, "Teleported " + player.getName() + " to " + + x + "," + y + "," + z);
        }
        return true;
    }