anchor.diff:  merge_acc_to_contents(MergeAcc) ->
       #merge_acc{keep=Keep, crdt=CRDTs} = MergeAcc,
       %% Convert the non-CRDT sibling values back to dict metadata values.
  -    Keep2 = lists:map(fun convert_from_dict_list/1, ordsets:to_list(Keep)),
  +    %%
  +    %% For improved performance, fold_contents/3 does not check for duplicates
  +    %% when constructing the "Keep" list (eg. using an ordset), but instead
  +    %% simply prepends kept siblings to the list. Here, we convert Keep into an
  +    %% ordset equivalent with reverse/unique sort.
  +    Keep2 = lists:usort(fun compare/2, lists:reverse(Keep)),
       %% Iterate the set of converged CRDT values and turn them into
       %% `r_content' entries.  by generating their metadata entry and
       %% binary encoding their contents. Bucket Types should ensure this
  
positive.code:         error ->
              undefined
      end.
  
  %% @doc Convert a r_content's inner dictionary to a list, and sort it to
  %%      ensure we can do comparsions between r_contents.
  convert_to_dict_list({r_content, Dict, Value}) ->
      {r_content, lists:usort(dict:to_list(Dict)), Value}.
  
  %% @doc Convert a r_content's inner dictionary from a list to a dict.
  convert_from_dict_list({r_content, Dict, Value}) ->
      {r_content, dict:from_list(Dict), Value}.
  
  %% @doc  Promote pending updates (made with the update_value() and
  %%       update_metadata() calls) to this riak_object.
  
negative.code: %% @doc Merge the r_objects contents by converting the inner dict to
  %%      a list, ensuring a sane order, and merging into a unique list.
  merge_contents(NewObject, OldObject, false) ->
      Result = lists:umerge(fun compare/2,
                            lists:usort(fun compare/2, NewObject#r_object.contents),
                            lists:usort(fun compare/2, OldObject#r_object.contents)),
      {undefined, Result};
  
  %% @private with DVV enabled, use event dots in sibling metadata to
  %% remove dominated siblings and stop fake concurrency that causes
  %% sibling explsion. Also, since every sibling is iterated over (some
  