anchor.diff:      {additional_field_name(K), F}.
   
   additional_field_name(N) when is_atom(N) ->
  -    list_to_atom("_" ++ atom_to_list(N)).
  +    F = atom_to_binary(N, utf8),
  +    <<"_", F/binary>>.
   
   syslog_severity(debug) ->
       7;
  
positive.code:                 {file, <<"undefined">>},
                  {host, <<"localhost">>},
                  {facility, <<"erlang">>},
                  {'_pid', <<"unknown">>},
                  {'_node', <<"undefined">>},
                  {'_application', <<"lager_graylog_backend">>},
                  {'_module', <<"undefined">>},
                  {'_function', <<"undefined">>}
                 ],
  
      ?assertEqual(lists:sort(Expected), lists:sort(Data)).
  
negative.code: get_pid(_) ->
      <<"malformed">>.
  
  format_metadata({K = pid, V}) ->
      {additional_field_name(K), get_pid(V)};
  format_metadata({K, V}) when is_binary(V) ->
      {additional_field_name(K), V};
  format_metadata({K, V}) ->
  