anchor.diff:        {error, _} ->
            tl(Http)
      end,
  -   {ok, [hd(Http) | Payload]}.   
  +   {ok, State#{ret => [hd(Http) | Payload]}}.   
   
   %%
   %%
  
positive.code: %%%
  %%%----------------------------------------------------------------------------
  
  http_io(Timeout, State) ->
     case
        [either ||
           Sock <- socket(State),
           send(Sock, State),
           recv(Sock, Timeout, State),
           unit(Sock, _)
        ]
     of
        {ok, Sock1, Pckt} ->
           unit(Sock1, Pckt, State);
        {error, _} ->
           Authority = uri:authority( lens:get(req_uri(), State) ),
           http_io(Timeout, maps:remove(Authority, State))
     end.
  
  %%
  
negative.code:    header/2,
     payload/1, 
     request/0, 
     request/1,
     require/1
  ]).
  
  -type m(A)    :: fun((_) -> [A|_]).
  