anchor.diff:  %%
   %%   When `Body = none', no <i>Content-Length</i> is sent, of course.
   %%
  -%% @spec send_http_body(socket(), binary() | none) ->
  +%% @spec send_http_body(socket(), iolist() | none) ->
   %%   ok
   
   send_http_body(Sock, none = _Body) ->
  
positive.code: 
  %% @doc Send GET request and retrieve response.
  %%
  %% @spec get(url(), [http_header()], binary(), Opts) ->
  %%   {ok, http_response()} | {error, Reason}
  
  get(URL, Headers, Body, Opts) ->
  
negative.code: 
  %% @doc Send POST request and retrieve response.
  %%
  %% @spec post(url(), [http_header()], iolist(), Options) ->
  %%   {ok, http_response()} | {error, Reason}
  
  post(URL, Headers, Body, Opts) ->
  