Discussion: Tracing across threads with non-blocking I/O

I'm curious as to how money might support cross-thread tracing in Java when thread pools are not involved? Specifically, I would be interested in correlating traces across one or more HTTP requests performed using an NIO-based HTTP client (e.g. [async-http-client](https://github.com/AsyncHttpClient/async-http-client)) where a callback interface is invoked via a separate worker thread to indicate completion and on which I would want to correlate/continue the trace from the thread that originally initiated the request.