public void DestroyEnemy(FastSlime _slime)
 {
     _slime.enabled = false;
     aliveFastSlimeCount -= 1;
     if (aliveFastSlimeCount <0) aliveFastSlimeCount = 0;
     fastSlimePool.Return(_slime);
 }
 // ------------------------------------------------------------------
 // Desc:
 // ------------------------------------------------------------------
 public void Return( FastSlime _slime )
 {
     ++idx;
     fastSlimes[idx] = _slime;
 }