[Twisted-web] Static.File and browser caching

Hello. Static.File doesn't seem to support any of the cache features that modern browsers use. There are various HTTP headers that govern this, including Etag, Cache-Control, Expires, etc. The Twisted server returns a comparatively minimal set of headers (hit twistedmatrix.com and look at the headers). Also, as far as I can tell, a "good citizen" HTTPD changes the response from a "200" to another response code that indicates "nothing new here", under certain circumstances. OR, it lets the browser figure that out... but it has to give the browser enough headers for it to do so. Is there a subclass of Static.File somewhere in Twisted that supports these features, or am I perhaps looking in the wrong place for this functionality? Thanks.