public CashRegisterBookViewModel(IXlsFileReader xlsFileReader,
                                         IDialogService showDialog,
                                         IBookAccountSettingsEndpoint settingsEndpoint,
                                         ICashRegisterBookEndpoint cashRegisterBookEndpoint)
        {
            _xlsFileReader            = xlsFileReader;
            _showDialog               = showDialog;
            _settingsEndpoint         = settingsEndpoint;
            _cashRegisterBookEndpoint = cashRegisterBookEndpoint;

            _bookName = "Blagajna";

            LoadDataCommand           = new DelegateCommand(LoadDataFromFile);
            SaveDataCommand           = new DelegateCommand(SaveToDatabase, CanSaveItems);
            AccountsSettingsCommand   = new DelegateCommand(OpenAccountsSettings);
            FilterDataCommand         = new DelegateCommand(FilterItems);
            ProcessItemCommand        = new DelegateCommand(ProcessItem, CanProcess);
            CalculationsReportCommand = new DelegateCommand(SumColumns);
        }