public static AuctionLogger GetInstance()
 {
     if(instance == null)
     {
         instance = new AuctionLogger();
         return instance;
     }
     else
     {
         return instance;
     }
 }
 public CurrencyService()
 {
     logger = AuctionLogger.GetInstance();
 }
 public AuctionService()
 {
     logger = AuctionLogger.GetInstance();
 }
 public CategoryService()
 {
     logger = AuctionLogger.GetInstance();
 }
 public ProductService()
 {
     logger = AuctionLogger.GetInstance();
 }