Added additional acceptance test for variant negotiation: "If any of the existing cache entries contains only partial content for the associated entity, its entity-tag SHOULD NOT be included in the If-None-Match header field unless the request is for a range that would be fully satisfied by that entry." (http://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html#sec13.6)
httpcomponents/httpclient/trunk/httpclient-cache/src/test/java/org/apache/http/impl/client/cache/TestProtocolRecommendations.java