anchor.diff:  %%
   encode_version({Major, Minor}) ->
      <<$H, $T, $T, $P, $/, (encode_value(Major))/binary, $., (encode_value(Minor))/binary>>.
  +
  +%%
  +encode_url(undefined) ->
  +   <<$/>>;
  +encode_url(Url)
  + when is_binary(Url) ->
  +   Url.
   
   %%
   %%
  
positive.code: 
  %%
  encode_http_request({Mthd, Url, _}=Msg, S) ->
     Http = iolist_to_binary([atom_to_binary(Mthd, utf8), $ , Url, $ , encode_version(S#http.version), $\r, $\n]),
     encode(Msg, [Http], S#http{is=header});
  encode_http_request({Mthd, Url, _, _}=Msg, S) ->
     Http = iolist_to_binary([atom_to_binary(Mthd, utf8), $ , Url, $ , encode_version(S#http.version), $\r, $\n]),
     encode(Msg, [Http], S#http{is=header}).
  
  encode_http_response({Status, _}=Msg, S) ->
  
negative.code:       [Type]           -> {Type, '*'}
     end.
  
  
  %%%------------------------------------------------------------------
  %%%
  %%% encoder
  