Re-add incomplete Merger code which was pulled from master so to not block a release.

Now adding it onto a branch

This reverts commit 1cb4159fdb667a0725436ac545c7aa5967570e5a.

Change-Id: Iab37cf0c7c9ed4dfd21189db1cf9f917357e0d9d
(cherry picked from commit 96ad760ebfd2a54a95659744bc031daa014781d8)