public void BorrowSingleBook_SingleBookGetsBorrowed()
{
var bookId = _screenHelper.Object.GetBookId();
var reader = _screenHelper.Object.GetNewReader();
var days = _screenHelper.Object.GetBorrowDays();
_borrow.BorrowSingleBook(bookId, reader, days);
_bookRepository.Verify(b => b.BorrowABook(bookId, reader, days), Times.Once);
}