anchor.diff:              generate_map_star(Map, Nodes, Options)
       end.
   
  -is_compatible_past_star_map(OptionsPast, OptionsNow, NumReplicas) ->
  +is_compatible_past_star_map(OptionsPast0, OptionsNow0, NumReplicas) ->
  +    OptionsPast = lists:keydelete(tags, 1, OptionsPast0),
  +    OptionsNow = lists:keydelete(tags, 1, OptionsNow0),
  +
       case OptionsNow =:= OptionsPast of
           true ->
               true;
  
positive.code:             CurrentNotCommon = sets:subtract(KeepNodesSet, CandidateNodesSet),
              case sets:size(CurrentNotCommon) of
                  0 ->
                      [CandidateMap];
                  1 ->
                      [NewNode] = sets:to_list(CurrentNotCommon),
                      [OldNode] = sets:to_list(sets:subtract(CandidateNodesSet, KeepNodesSet)),
                      NewMap = misc:rewrite_value(OldNode, NewNode, CandidateMap),
                      [NewMap];
                  2 ->
                      [NewNodeA, NewNodeB] = sets:to_list(CurrentNotCommon),
                      [OldNodeA, OldNodeB] = sets:to_list(sets:subtract(CandidateNodesSet, KeepNodesSet)),
                      NewMapA = misc:rewrite_value(OldNodeB, NewNodeB,
                                                   misc:rewrite_value(OldNodeA, NewNodeA, CandidateMap)),
                      NewMapB = misc:rewrite_value(OldNodeA, NewNodeB,
                                                   misc:rewrite_value(OldNodeB, NewNodeA, CandidateMap)),
                      [NewMapA, NewMapB];
                  _ ->
                      %% just try some random mapping just in case. It
                      %% will work nicely if NewNode-s are all being
  
negative.code:                     %% removed). Because in such case exact mapping
                      %% doesn't really matter, because we'll backfill
                      %% new nodes and it doesn't matter which.
                      CandidateNotCommon = sets:to_list(sets:subtract(CandidateNodesSet, KeepNodesSet)),
  
                      rewrite_map(CandidateMap, CandidateTags, CurrentTags,
                                  lists:zip(CandidateNotCommon, sets:to_list(CurrentNotCommon)))
              end
      end.
  
  