public EnemyUnit CreateBonusUnit(int number)
    {
        EnemyUnitData enemyUnitData = unitFactory.CreateEnemyUnitDataForBonus(number);
        EnemyUnit     enemy         = Instantiate(bonusUnit, bonusUnitSpawnLocation).GetComponent <EnemyUnit>();

        enemy.InitializeEnemyUnitGameObject(enemyUnitData, enemyUnitData.GetMaxHealth());

        return(enemy);
    }