docs: protected Address determineMergeLeader(Map<Address,View> views) {
          // we need the merge *coordinators* not merge participants because not everyone can lead a merge !
          Collection<Address> coords=Util.determineActualMergeCoords(views);
          if(coords.isEmpty())
              coords=Util.determineMergeCoords(views); // https://issues.jboss.org/browse/JGRP-2092
          if(coords.isEmpty()) {
              log.error("%s: unable to determine merge leader from %s; not starting a merge", gms.local_addr, views);
              return null;
          }
          return new Membership(coords).sort().elementAt(0); // establish a deterministic order, so that coords can elect leader
      }