private static void CollidePlayerBullet(PlayerVerticalShooter player, EnemyBullet bullet)
 {
     player.InflictDamage(bullet);
     bullet.InflictDamage(player);
 }
 private static void CollidePlayerEnemy(PlayerVerticalShooter player, EnemyShip enemy)
 {
     player.InflictDamage(enemy);
     enemy.InflictDamage(player);
 }