private void _timer_Elapsed(object sender, ElapsedEventArgs e)
        {
            var snapshots = new List <SnapshotData>();
            var tasks     = _currencyPairs.Select(currencyPair =>
            {
                Interlocked.Increment(ref _requestId);
                return(_connector.FetchData(currencyPair, (o, data) => snapshots.Add(data)));
            }).ToArray();

            Task.WaitAll(tasks);
            _exporter.Export(snapshots);
        }
 private void Handler(object sender, StreamingData e)
 {
     _exporter.Export(new[] { e });
 }