private async void PersistCache(object state)
        {
            _timer.Change(Timeout.Infinite, Timeout.Infinite);

            try
            {
                var pairs = _cacheService.GetAll();

                await _repository.Write(pairs);
            }
            catch (Exception ex)
            {
                await _log.WriteErrorAsync(Constants.ComponentName, null, null, ex);
            }
            finally
            {
                _timer.Change(_settings.CacheSettings.PersistPeriod, Timeout.InfiniteTimeSpan);
            }
        }