anchor.diff:                     Headers, exml:to_iolist(Body),
                      infinity, []).
   
  -send(Transport, Body, #state{requests = Requests} = S) ->
  +send(Transport, Body, State) ->
  +    send(Transport, Body, State#state.rid+1, State).
  +
  +send(Transport, Body, NewRid, #state{requests = Requests} = S) ->
       Ref = make_ref(),
       Self = self(),
       AsyncReq = fun() ->
  
positive.code: 
  %% Low level API
  -export([send_raw/2,
           get_sid/1,
           get_rid/1,
           get_keepalive/1,
  
negative.code:             Self ! {http_reply, Ref, Reply, Transport}
      end,
      NewRequests = [{Ref, proc_lib:spawn_link(AsyncReq)} | Requests],
      S#state{rid = NewRid, requests = NewRequests}.
  
  sync_send(Transport, Body, S=#state{}) ->
      {ok, Reply} = request(Transport, Body),
  