Ability to do sub-file customisation (suppression) of conformance rules

I'm experimenting with conformance rules but have found I need to suppress a few specific violations, and would rather do this on individual functions than for an entire file.

I haven't found how to do this, other than rolling my own solution (adding support for using `@suppress {conformanceViolations}` as in https://github.com/google/closure-compiler/pull/1199, or by writing my own warnings guard which read some proprietary hints file).

Quite often this is because there is some compiler oddity, perhaps a bug which I would file, but in the interim would want to maintain my project's "clean slate" warnings policy.

Am I missing something and is this already possible? If not please could you reconsider the very low risk single line changing PR https://github.com/google/closure-compiler/pull/1199. Currently I have to maintain a custom fork for this change.