anchor.diff:                  end, Acc, Chain)
         end, sets:new(), Map).
   
  -matching_renamings(KeepNodesSet, CurrentMap, CandidateMap) ->
  +matching_renamings(KeepNodesSet, CurrentMap, CandidateMap, Trivial) ->
       matching_renamings_with_tags(KeepNodesSet,
  -                                 {CurrentMap, undefined}, {CandidateMap, undefined}).
  -
  -matching_renamings_with_tags(KeepNodesSet,
  -                             {CurrentMap, CurrentTags0}, {CandidateMap, CandidateTags0}) ->
  +                                 {CurrentMap, undefined},
  +                                 {CandidateMap, undefined}, Trivial).
  +
  +matching_renamings_with_tags(KeepNodesSet, {CurrentMap, CurrentTags0},
  +                             {CandidateMap, CandidateTags0}, Trivial) ->
       CurrentTags = case CurrentTags0 of
                         undefined ->
                             [];
  
positive.code:                   lists:zip(OldNodes, NewNodes) ++ Acc
            end, [], TagRenaming),
  
      [do_rewrite(CandidateMap, MapRenaming)].
  
  build_tag_renaming([]) ->
      [];
  
negative.code:             case length(hd(CandidateMap)) =:= length(hd(CurrentMap)) of
                  true ->
                      matching_renamings_same_vbuckets_count(KeepNodesSet, CurrentTags,
                                                             CandidateMap, CandidateTags, Trivial);
                  false ->
                      []
              end
  