anchor.diff:                                {'application', <<"lager_graylog_backend">>},
                                 {'module', <<?MODULE_STRING>>},
                                 {'line', <<"42">>},
  -                              {'pid', iolist_to_binary(pid_to_list(self()))}
  +                              {'pid', iolist_to_binary(pid_to_list(self()))},
  +                              {'crap', <<"{sink,<<208,156,208,149,208,148,208,146,208,149,208,148,208,152>>}">>},
  +                              {'notcrap', <<"БАЛАЛАЙКА"/utf8>>}
                                ]}),
   
       ?assertEqual(<<Expected/binary,"\n">>, Data).
  
positive.code: 
  format_3_test() ->
      Now = os:timestamp(),
      MD = [{application, lager_graylog_backend}, {module, ?MODULE}, {line, 42}, {pid, self()}],
      Cfg = [{host, "localhost"}],
  
      Message = lager_msg:new("a message", Now, info, MD, []),
  
negative.code: format_metadata({K, V}) when is_atom(V)    -> {true, {K, atom_to_binary(V, utf8)}};
  format_metadata({K, V}) ->
      {true,
          {K, try unicode:characters_to_binary(V) catch
              _:_ -> iolist_to_binary(lager_trunc_io:fprint(V, 1024))
          end}
      }.
  
  