public async Task HandleAsync(UpdateEntryCommand command)
        {
            var phoneBook = await _phoneBookRepository.GetPhoneBookByIdAsync(command.PhoneBookId);

            phoneBook.UpdateEntry(command.EntryId, command.Name, command.PhoneNumber);
            _phoneBookRepository.Update(phoneBook);
            await _phoneBookRepository.SaveAsync();
        }
        public async Task HandleAsync(InsertEntryCommand command)
        {
            var phoneBook = await _phoneBookRepository.GetPhoneBookByIdAsync(command.PhoneBookId);

            if (phoneBook.Entries.Where(a => a.Name == command.Name && a.PhoneNumber == command.PhoneNumber).Any())
            {
                throw new ValidateException("Phone book entry already exists");
            }
            phoneBook.InsertEntry(command.Name, command.PhoneNumber);
            _phoneBookRepository.Update(phoneBook);
            await _phoneBookRepository.SaveAsync();
        }