anchor.diff:        next(Req2, State2, fun send_req_headers/2)
     end.
   
  -send_req_headers(Req, State=#state{conn=Conn, req_headers=ReqHeaders, backend=Backend}) ->
  +send_req_headers(Req, State=#state{req_headers=ReqHeaders, backend=Backend}) ->
     FormattedHeaders = [case Name of
       <<"host">> ->
         format_header(Name, format_host_header(Backend));
  
positive.code:       no_call
    end.
  
  next(Req, State, Next) when is_function(Next) ->
    Next(Req, State);
  next(Req, State, StatusCode) when is_integer(StatusCode) ->
    respond(Req, State, StatusCode).
  
  respond(Req, State, StatusCode) ->
    {ok, Req2} = cowboy_req:reply(StatusCode, Req),
  
negative.code:     {<<Prefix/binary, "-port">>, integer_to_binary(Port)},
      {<<Prefix/binary, "-path">>, Path}
    ].
  
  atom_to_binary(Val) ->
    list_to_binary(atom_to_list(Val)).
  
  %% Protocol
  
  