This is from a TODO in the code ("Figure out where/if WrapTransient should be used"), but it may be relevant for multiple handlers.

This is about indicating "transient" status in errors if there are any handlers that are expected to occasionally fail with transient errors.

Relevant library:
https://cs.chromium.org/chromium/infra/go/src/go.chromium.org/luci/common/retry/transient/transient.go

Example usage:
https://cs.chromium.org/chromium/infra/go/src/infra/monorail/endpoints.go?l=36
https://cs.chromium.org/chromium/infra/go/src/go.chromium.org/luci/grpc/prpc/client.go?l=113