private void PlaceOnBattleField(Player p)
        {
            bool placed = false;

            foreach (BattleField b in battlefields)
            {
                placed = b.AcceptPlayer(p);
                if (placed)
                {
                    break;
                }
            }
            if (!placed)
            {
                BattleField new_battlefield = new BattleField();
                new_battlefield.AcceptPlayer(p);
                battlefields.Add(new_battlefield);
            }
        }