FreezePlayers - Zamrażanie graczy!

import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.command.Command;
import org.bukkit.command.CommandExecutor;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.player.PlayerMoveEvent;
import org.bukkit.plugin.java.JavaPlugin;

import java.util.HashSet;
import java.util.Set;
import java.util.UUID;

public class Freeze extends JavaPlugin implements CommandExecutor, Listener
{
    private final Set<UUID> uuids = new HashSet<>();

    @Override
    public void onEnable()
    {
        getCommand("freeze").setExecutor(this);
        Bukkit.getPluginManager().registerEvents(this, this);
    }

    @Override
    public void onDisable()
    {
        // do something
    }

    @Override
    public boolean onCommand(CommandSender sender, Command command, String label, String[] args)
    {
        if (!(sender instanceof Player))
        {
            return true;
        }
        final Player player = (Player) sender;
        if (!player.hasPermission("freeze"))
        {
            player.sendMessage(fixColors("&cBrak uprawnien!"));
            return true;
        }
        if (args.length == 1)
        {
            final UUID uuid = Bukkit.getPlayer(args[0]).getUniqueId();
            if (uuids.contains(uuid))
            {
                player.sendMessage(fixColors("&cOdmrozono gracza o uuid &7" + uuid.toString()));
                uuids.remove(uuid);
            }
            else
            {
                player.sendMessage(fixColors("&cZamrozono gracza o uuid &7" + uuid.toString()));
                uuids.add(uuid);
            }
            return true;
        }
        player.sendMessage(fixColors("&cUzycie: &7/freeze [nick]"));
        return true;
    }

    @EventHandler
    public void onMove(PlayerMoveEvent event)
    {
        final UUID uuid = event.getPlayer().getUniqueId();
        if (!uuids.contains(uuid))
        {
            return;
        }
        event.setCancelled(true);
    }

    private String fixColors(final String content)
    {
        return ChatColor.translateAlternateColorCodes('&', content);
    }
}