We've introduced our first link in https://github.com/eic/EDM4eic/pull/108. The upstream changes for reference are: * https://github.com/key4hep/EDM4hep/commit/ac7ceab53cb59d8e47dc0dc74530bf86a2f8b1ba * https://github.com/key4hep/EDM4hep/commit/d651cd6792eb29808c18f742280508735f040269