- prepare-request #!optional preparerparameter
Here, preparer is a procedure which will be called every time a connection is made. This includes every request in a redirect chain, so you can decide for every URL in the chain what to do with the request. The procedure receives and must return an intarweb request object. The default implementation is default-prepare-request.
CAVEAT: If you decide to change the request-uri last-minute, you must also set the host header, because it will have already been initialized to the request-uri's host attribute.