Last.fm API: are Etag/Last-Modified headers supported?

When using the REST interface for Last.fm web service, are the "Etag" and/or "Last-Modified" HTTP headers provided in the responses?

E.g. let's say I plan on using the track.getTags API me开发者_运维问答thod, is either "Etag" / "Last-Modified" HTTP header sent along with the response?

(NOTE: I have asked the same question on Last.fm's "discussion board" but it seems there is low activity there... I am probing SO's vast collective knowledge here)

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From a conversation with a last.fm developer, it seems that this functionality isn't supported at the moment... or least not consistently.