LGTM, Thanks! Just a minor suggestion.
http://codereview.appspot.com/217091/diff/3011/2006 File java/gadgets/src/main/java/org/apache/shindig/gadgets/uri/ConcatUriManager.java (right): http://codereview.appspot.com/217091/diff/3011/2006#newcode160 java/gadgets/src/main/java/org/apache/shindig/gadgets/uri/ConcatUriManager.java:160: List<String> version(List<List<Uri>> resourceUris, String container); Since this is a specific versioner, you might save some code by passing in ConcatUri instead of Uri (for both version and validate) http://codereview.appspot.com/217091/show
