public boolean contestCommand(CommandSender sender, String[] args) {
        if (args.length != 0) {
            return false;
        } else if (sender instanceof  Player) {
            Player player = ((Player) sender).getPlayer();
            MCWarClanPlayer mcPlayer = _tc.getPlayer(player.getUniqueId());
            Base currentBase = mcPlayer.getCurrentBase();
            if (mcPlayer.isBarbarian()) {
                Messages.sendMessage("You cannot contest a base when you are a member of " + mcPlayer.getColoredTeamName(), Messages.messageType.INGAME, player);
            } else if (currentBase != null && !currentBase.isEnemyToPlayer(mcPlayer)) {
                Messages.sendMessage("Use your mind... you cannot attack your own team base !", Messages.messageType.INGAME, player);
            } else if (!mcPlayer.hasBases()) {
                Messages.sendMessage("You need at least one Head Quarter, then you could launch any battle you want !", Messages.messageType.INGAME, player);
            } else if (currentBase == null) {
                Messages.sendMessage("You're not in an enemy base, you cannot contest this territory.", Messages.messageType.INGAME, player);
            } else if (!currentBase.hasEnoughTeamMatesToBeAttacked()) {
                Messages.sendMessage("Not enough players connected in " + currentBase.getTeamColoredName() + " to attack them.", Messages.messageType.INGAME, player);
            } else if (currentBase.isContested()) {
                Messages.sendMessage("This team is already attacked by another team. But nothing forbid you to help one of these two...", Messages.messageType.INGAME, player);
            } else {
                currentBase.isContested(true);
                // Inform the two teams !
                Team attackedTeam = currentBase.get_team();
                Team attackingTeam = mcPlayer.get_team();
                attackedTeam.sendMessage(currentBase.get_name() + " is attacked by " + attackingTeam.getColoredName() + " !");
                attackingTeam.sendMessage("Your team is attacking " + attackedTeam.getColoredName() + " !");

                //Create a new thread in order to check if the enemies are defeated
                BukkitTask tks = new MCWarClanRoutine.ContestedBaseRoutine(currentBase,
                        attackingTeam).runTaskTimer(_plugin,
                        0, 100);
            }
        } else {
            Messages.sendMessage("You have to be a player to perform this command !", Messages.messageType.INGAME, sender);
        }
        return true;
    }