Cange Cache-Control for documents retrieved from Document Service

Hello,

we currently use the document service to store common images that are delivered to the clients using a Proxy Bridge (extends AbstractCmisProxyServlet). How can we change the Cache-Control header for the content response? The documents should be cacheable by any proxy and at 24 hours valid. The default just returns:

Cache-Control →private, max-age=0

Any hint or documentation link is welcome!