private void OnCollisionEnter(Collision collision)
 {
     if (collision.gameObject.tag == "EnemyBullet")
     {
         playerLife.addDamage(25);
     }
 }
 private void OnTriggerStay(Collider other)
 {
     if (other.gameObject == player)
     {
         if (Time.time > nextFire)
         {
             nextFire = Time.time + fireRate;
             playerLife.addDamage(40);
         }
     }
 }