anchor.diff:  
   
   %% @doc Handle a fail process
  -%%
   -spec(handle_fail(atom(), list({integer(), string()})) ->
                ok | {error, any()}).
   handle_fail(_, []) ->
  
positive.code:         ok ->
              ok;
          {error, Cause} ->
              ?warn("compare_metadata/1",
                    [{qid, QId}, {cluster_id, ClusterId},
                     {addr_id, AddrId}, {key, Key}, {cause, Cause}]),
              ok
  
negative.code: 
  %% @doc Compare a local-metadata with a remote-metadata
  %%      If it's inconsistent, the metadata is put into the queue
  -spec(compare_metadata(ListOfMetadata) ->
               ok when ListOfMetadata::[#?METADATA{}]).
  compare_metadata([]) ->
  