Proto gets the protocol used as the transport.

ScrubAnswer is returned when the reply has been scrubbed by removing RRs from the answer section.

ScrubExtra is returned when the reply has been scrubbed by removing RRs from the additional section.

ScrubIgnored is returned when Scrub did nothing to the message.

Request contains some connection state and is useful in plugin.

Result is the result of Scrub.