private void RespondToCollisionWithMario(Side side, IObject obj)
        {
            Mario mario = (Mario)obj;

            if (mario.IsStar || mario.PowerLevel() == MarioPowerLevel.Metal)
            {
                this.Spiny.Kill();
            }
            else if (SideGeneralizer.IsBottom(side))
            {
                this.Spiny.Kill();
            }
        }
        private void RespondToCollisionWithMario(Side side, IObject obj)
        {
            Mario mario = (Mario)obj;

            if (mario.IsStar || mario.PowerLevel() == MarioPowerLevel.Metal)
            {
                this.Koopa.SetDead();
            }
            else if (SideGeneralizer.IsTop(side))
            {
                this.Koopa.WillBecomeShell = true;
                this.Koopa.SetStomped();
            }
        }