HTTPProducer is currently copying all the older headers from IN onto the OUT.
This means that after doing an HTTP call, there is no way to know which headers where returned by destination server, and which were there originally.
In my case this is disastrous because I need to do an HMAC which include all headers
Please add an HttpEndpoint Options which allows to disable that behaviour and not copy any old headers from IN. (and yes in that case the original headers would get lost, but then the developer can just preserve whatever he needs by storing the data in the exchange properties)