docs: public void restoreGroupMembers(long logIndex, Collection<Endpoint> members) {
          assert lastGroupMembers.index() <= logIndex
                  : "Cannot restore group members to: " + members + " at log index: " + logIndex + " because last group members: "
                  + lastGroupMembers + " has a bigger log index.";
  
          // there is no leader state to clean up
  
          RaftGroupMembers groupMembers = new RaftGroupMembers(logIndex, members, localEndpoint);
          this.committedGroupMembers = groupMembers;
          this.lastGroupMembers = groupMembers;
      }