public void BuyItem(Person person, Item ıtem, GameCampaign gameCampaign = null) { if (_playerService.CheckPlayerExistence(person, person) && gameCampaign != null) { _sellService.Sell(person, ıtem, gameCampaign); _gameCampaignService.Delete(gameCampaign, person); } else if (_playerService.CheckPlayerExistence(person, person) && gameCampaign == null) { _sellService.Sell(person, ıtem, gameCampaign); } }