Hi, as written in the JIRA comment https://issues.apache.org/jira/browse/CXF-7601?focusedCommentId=16750000&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-16750000 there is now a branch for the implementation with a working draft.
Cheers Dennis
