private async Task ValidatePostBookAsync(BookMobilePostDto bookDto, Book book)
{
var bookExistsInChosenOffice = book
.BookOffices
.Any((l => l.OfficeId == bookDto.OfficeId));
_serviceValidator.ThrowIfBookExist(bookExistsInChosenOffice);
var officeExists = await _officeDbSet.AnyAsync(o => o.Id == bookDto.OfficeId);
_serviceValidator.ThrowIfOfficeDoesNotExist(officeExists);
}
