public void EditReader()
        {
            var reader = readersTable.SelectedItem as Reader;

            if (reader != null)
            {
                var readersAddingWindow = new AddNewReaderWindow(_unitOfWork, _readersDisplayViewModel, reader);
                readersAddingWindow.ShowDialog();
            }
        }
        private void addBookButton_Click(object sender, RoutedEventArgs e)
        {
            var readerCreatingWindow = new AddNewReaderWindow(_unitOfWork, _readersDisplayViewModel);

            readerCreatingWindow.ShowDialog();
        }