These are intended only for debug printing and error messages for the most
common protocol types that you need to know the contents of.
Change-Id: I1f0f7b17b4b12c3b26096b46808bce37c3722ced
Reviewed-on: https://go-review.googlesource.com/c/150037
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
Ian Cottrell