private LibraryProxy(DBFactoryEnums factoryEnums)
        {
            ILibraryFactory libraryFactory;

            switch (factoryEnums)
            {
            case DBFactoryEnums.MsAccess:
                libraryFactory = new Ms_Access.LibraryFactory();
                break;

            case DBFactoryEnums.MsAccessPassword:
                libraryFactory = new MsAccessPassword.LibraryFactory();
                break;

            case DBFactoryEnums.MDBPassword:
                libraryFactory = new MDBPassword.LibraryFactory();
                break;

            case DBFactoryEnums.MySql:
                libraryFactory = new MySql.LibraryFactory();
                break;

            case DBFactoryEnums.MsSQLServerExpress:
                libraryFactory = new MsSQLServerExpress.LibraryFactory();
                break;

            default:
                throw new NotImplementedException();
            }

            AccountMehod = libraryFactory.CreateAccount();
            BookMethod   = libraryFactory.CreateBook();
            BorrowMehod  = libraryFactory.CreateBorrow();
        }