private async Task <DnsMessage> DoQuery(DnsMessage dnsMessage, string ipEndPoint)
{
var upstreamResponse = await _strategyManager
.ResolveAsync(dnsMessage, ipEndPoint, _cancellationTokenSource.Token)
.ConfigureAwait(false);
if (upstreamResponse?.AnswerRecords != null &&
upstreamResponse.AnswerRecords.Any())
{
return(upstreamResponse);
}
return(await Task.FromResult((DnsMessage)null).ConfigureAwait(false));
}