private void OnTriggerEnter(Collider other)
    {
        if (other.gameObject.tag == "Player")
        {
            unit           = other.gameObject.GetComponent <PlayerInfo>();
            targetAcquired = true;
        }
        else
        {
            if (other.gameObject.tag == "Enemy" && sender == "Player")
            {
                unit           = other.gameObject.GetComponent <EnemyInfo>();
                targetAcquired = true;
            }
        }

        if (other.gameObject.tag == "Player" && sender == "Player")
        {
            targetAcquired = false;
        }

        if (unit != null && targetAcquired)
        {
            unit.Hurt(damage);
            Destroy(gameObject);
            targetAcquired = false;
        }
    }