anchor.diff:  %% there is no response within `Timeout' milliseconds, the request is
   %% canceled and `{error, timeout}' is returned.
   %% @end
  --spec send_body_part(upload_state(), iolist() | 'http_eob', timeout()) -> result().
  +-spec send_body_part(upload_state(), iodata() | 'http_eob', timeout()) -> result().
   send_body_part({Pid, _Window}, http_eob, Timeout) when is_pid(Pid) ->
       Pid ! {body_part, self(), http_eob},
       read_response(Pid, Timeout);
  
positive.code: %%   Hdrs = [{Header, Value}]
  %%   Header = string() | binary() | atom()
  %%   Value = string() | binary()
  %%   RequestBody = iolist()
  %%   Timeout = integer() | infinity
  %%   Options = [Option]
  %%   Option = {connect_timeout, Milliseconds | infinity} |
  
negative.code: %%   Hdrs = [{Header, Value}]
  %%   Header = string() | binary() | atom()
  %%   Value = string() | binary()
  %%   RequestBody = iodata()
  %%   Timeout = integer() | infinity
  %%   Options = [Option]
  %%   Option = {connect_timeout, Milliseconds | infinity} |
  