public async Task IndexAsnyc(CancellationToken cancellationToken = default)
        {
            await Sync.WaitAsync(cancellationToken);

            try {
                if (!await _searchRepository.IndexExistsAsync(cancellationToken))
                {
                    _logger.LogInformation("Creating Elastic index");
                    await _searchRepository.CreateIndexAsync(cancellationToken);
                }

                var expectedCount = await _contentRepository.CountAsync(cancellationToken);

                var actualCount = await _searchRepository.CountAsync(cancellationToken);

                if (expectedCount != actualCount)
                {
                    var count    = 0;
                    var page     = 1;
                    var pageSize = 1000;
                    while (count < expectedCount)
                    {
                        _logger.LogInformation("Indexing elastic documents {Count} / {Total}", count, expectedCount);
                        var docs = await _contentRepository.ListAsync(page ++, pageSize, cancellationToken);

                        await _searchRepository.IndexAsync(docs.Select(_mapper.Map <Models.Elastic.Content>), cancellationToken);

                        count += docs.Count;
                    }
                }

                _logger.LogInformation("Elastic index is up to date");
            }
            finally {
                Sync.Release();
            }
        }