How to enable caching with GAE

I want to enable public caching with google app engine. I've got the following response where performance significantly increased 开发者_开发百科when starting to use the Cache-Control:

HTTP/1.0 200 OK =>
Cache-Control => public,max-age=86400
Content-Type => application/vnd.google-earth.kml+xml
Expires => Thu, 01 Dec 1994 16:00:00 GMT
Date => Sun, 10 Apr 2011 14:32:09 GMT
Server => Google Frontend

How can I now enable caching? Is it already enabled? Do I also need to add a future expires header? If so, how do I set the expires header? Thanks for any answer

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Yes, this enables caching - though you shouldn't be setting an expires header yourself at all unless it's accurate - just set the max-age, and let the caches and/or browser to determine the expiry date.