anchor.diff:              {ok, Req1} = cowboy_req:reply(500, [], stringify(Reason), Req0),
               {stop, Req1, State};
           [] ->
  -            {false, Req0, State};
  +            Req1 = set_cross_domain(Req0),
  +            {false, Req1, State};
           Metadata ->
               {true, Req0, State#{exists := true, metadata := Metadata}}
       end.
  
positive.code: 
  handle_json_method(Req, #{exists := false} = State, <<"GET">>) ->
      {false, Req, State};
  handle_json_method(Req, #{exists := true,
                           identifier := Identifier,
                           metadata := Metadata} = State, <<"GET">>) ->
      {dbyr_identifier:to_json(Identifier, Metadata), Req, State};
  handle_json_method(Req, #{identifier := Identifier} = State, <<"POST">>) ->
      {Metadata, Req1} = case cowboy_req:body(Req) of
          {ok, <<>>, R1} ->
              {[], R1};
          {ok, Body, R1} ->
  
negative.code:             {ok, Req1} = cowboy_req:reply(500, [], stringify(Reason), Req0),
              {stop, Req1, State};
          ok ->
              Req1 = set_cross_domain(Req0),
              {true, Req1, State}
      end.
  
  content_types_accepted(Req, State) ->
  