public async Task <IActionResult> GetAsync()
{
var timeout = TimeSpan.FromSeconds(_options.Value.SampleTimeoutSeconds);
var cancel = new CancellationTokenSource(timeout);
var samples = await Task.Run(() => _registry.SelectMany(x => x.GetSample()).ToImmutableDictionary(), cancel.Token);
var json = JsonSampleSerializer.Serialize(samples);
return(Ok(json));
}