This will allow varying implementations and wrappers, and more
closely matches the concepts used in the net library.
Change-Id: I4be4c6efb3def0eda2693f482cbb0c6f776e5642
Reviewed-on: https://go-review.googlesource.com/c/tools/+/232877
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
