anchor.diff:  
   handle_app_recv_unknown(ContentType, App, Options, State) ->
       Timeout = proplists:get_value(recv_timeout, Options, ?IDLE_TIMEOUT),
  +    maybe_send_continue(State),
       Received = recv_remaining(Timeout, State),
       handle_app_recv_unknown_(Received, ContentType, App, State).
   
  
positive.code:     maybe_send_continue(State),
      start_recv_multipart(TypeParams, App, Options, State).
  
  maybe_send_continue(State) ->
      case expect_continue(State) of
          true -> send_continue(State);
          false -> ok
      end.
  
  expect_continue(State) ->
      req_header("Expect", State) == "100-continue".
  
  send_continue(#state{sock=Sock}) ->
      Line = ["HTTP/1.1 100 Continue", ?CRLF, ?CRLF],
      ok = gen_tcp:send(Sock, Line).
  
  start_recv_multipart(TypeParams, App, Options, State) ->
      Length = proplists:get_value(recv_length, Options, ?DEFAULT_RECV_LEN),
      Timeout = proplists:get_value(recv_timeout, Options, ?IDLE_TIMEOUT),
  
negative.code: 
  handle_app_recv_urlencoded_data(App, Options, State) ->
      Timeout = proplists:get_value(recv_timeout, Options, ?IDLE_TIMEOUT),
      maybe_send_continue(State),
      Received = recv_remaining(Timeout, State),
      handle_app_recv_urlencoded_data_(Received, App, State).
  
  