public async Task <ActionResult <PhoneBookResponse> > GetPhoneBooks([FromQuery] PagingRequest pagingRequest)
        {
            Guid userId          = Guid.Parse(_userInfoService.UserId);
            int  phoneBooksCount = await _phoneBookRepository.CountForUserAsync(userId);

            IReadOnlyList <PhoneBook> phoneBooks = await _phoneBookRepository
                                                   .GetPhoneBooksForUser(userId, pagingRequest.Page, pagingRequest.PageSize);

            PagingInfo pagingInfo = new PagingInfo(phoneBooksCount, pagingRequest.Page, pagingRequest.PageSize);

            Response.Headers.Add("X-Pagination",
                                 JsonConvert.SerializeObject(pagingInfo,
                                                             new JsonSerializerSettings()
            {
                ContractResolver = new CamelCasePropertyNamesContractResolver()
            }));
            return(Ok(_mapper.Map <IEnumerable <PhoneBookResponse> >(phoneBooks)));
        }