private async Task OnViewXML(OWINEnv env, Dictionary<string, string> query, CancellationToken cancel_token)
{
var data = BuildViewXml();
env.SetResponseStatusCode(HttpStatusCode.OK);
env.SetResponseHeader("Content-Type", "text/xml");
env.SetResponseHeader("Content-Length", data.Length.ToString());
if (env.RequestMethod!="HEAD") {
await env.ResponseBody.WriteAsync(data, 0, data.Length, cancel_token).ConfigureAwait(false);
}
}