private async Task SendJson(OWINEnv env, JToken token, bool send_body, CancellationToken cancel_token)
{
var body = System.Text.Encoding.UTF8.GetBytes(token.ToString());
env.AddResponseHeader("Content-Type", "application/json");
env.AddResponseHeader("Content-Length", body.Length.ToString());
env.ResponseStatusCode = (int)HttpStatusCode.OK;
if (send_body) {
await env.ResponseBody.WriteAsync(body, 0, body.Length, cancel_token);
}
}