anchor.diff:              {ok, {{_Version, 200, _ReasonPhrase}, _Headers, Body}} =
                 http:request(post,
                              {"http://" ++ Host ++ Path,
  -                            [{"User-Agent", "Erlang/thrift_http_transport"}],
  +                            [{"User-Agent", "Erlang/thrift_http_transport"} | ExtraHeaders],
                               "application/x-thrift",
                               WBinary},
                              HttpOptions,
  
positive.code:                              path = Path,
                               read_buffer = [],
                               write_buffer = [],
                               http_options = []},
      ApplyOption =
          fun
              ({http_options, HttpOpts}, State = #http_transport{}) ->
                  State#http_transport{http_options = HttpOpts};
              (Other, #http_transport{}) ->
                  {invalid_option, Other};
              (_, Error) ->
  
negative.code:                                  path = Path,
                                   read_buffer = Rbuf,
                                   write_buffer = Wbuf,
                                   http_options = HttpOptions,
                                   extra_headers = ExtraHeaders}) ->
      case iolist_to_binary(Wbuf) of
          <<>> ->
              %% Don't bother flushing empty buffers.
  