private void OnTriggerEnter2D(Collider2D collision)
        {
            if (gameObject.name != "Boss")
            {
                PlayerUnit pu = collision.gameObject.GetComponent <PlayerUnit>();

                if (pu)
                {
                    pu.GetComponent <Collider2D>().enabled = false;
                    Debug.Log("Bye" + gameObject.name);
                    pu.Die(vD, vS);
                }
                else
                {
                    PlayerShrink ps = collision.gameObject.GetComponent <PlayerShrink>();

                    if (ps)
                    {
                        if (lazer)
                        {
                            firstHitTime = Time.time;
                        }
                        else
                        {
                            ps.Die(vD, vS);
                        }
                    }
                }
            }
        }
        private void OnTriggerStay2D(Collider2D collision)
        {
            PlayerShrink ps = collision.gameObject.GetComponent <PlayerShrink>();

            if (ps)
            {
                if (lazer && Time.time > (firstHitTime + (1.0f / (float)dmgPerSecond)))
                {
                    ps.Die(vD, vS);
                    firstHitTime = Time.time;
                }
            }
        }