testing: add doc to not call Init concurrently
Change-Id: I2e218805fbe4858be125df97bdaf921799315799
GitHub-Last-Rev:
32b798d75f7ec0f72e18a65932ad93d8e5f1040a
GitHub-Pull-Request: golang/go#62410
Reviewed-on: https://go-review.googlesource.com/c/go/+/525015
Auto-Submit: Ian Lance Taylor <iant@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>