void SetAppropriateBulletPool()
    {
        switch (bulletType)
        {
        case BulletType.SLOW:
            bulletPool = SimpleBulletPool.GetPool(SimpleBulletPool.BulletPoolType.ENEMY_SLOW);
            break;

        case BulletType.NORMAL:
            bulletPool = SimpleBulletPool.GetPool(SimpleBulletPool.BulletPoolType.ENEMY_NORMAL);
            break;

        case BulletType.FAST:
            bulletPool = SimpleBulletPool.GetPool(SimpleBulletPool.BulletPoolType.ENEMY_FAST);
            break;

        default:
            throw new UnityException("unknown bullet type " + bulletType.ToString());
        }
    }
 void Start()
 {
     normalBulletPool = SimpleBulletPool.GetPool(SimpleBulletPool.BulletPoolType.FRIENDLY_NORMAL);
     fastBulletPool   = SimpleBulletPool.GetPool(SimpleBulletPool.BulletPoolType.FRIENDLY_FAST);
     RespawnReset();
 }