anchor.diff:  tcp_connect(Uri, #state{socket = Sock0, so = SOpt} = State) ->
      [$^ ||
         connect(Uri, Sock0, SOpt),
  -      fun(Sock1) -> {ok, State#state{socket = Sock1}} end 
  +      fmap(State#state{socket = _})
      ].
   
   
  
positive.code: getstat(#socket{in = In, eg = Eg}) ->
     pstream:packets(In) + pstream:packets(Eg).
  
  %%%------------------------------------------------------------------
  %%%
  %%% private
  
negative.code:    [$^ ||
        fmap(pipe:a(Pipe, {tcp, self(), {terminated, Reason}})),
        fmap(State)
     ].
  
  %%
  tcp_downlink_send(Pckt, #state{socket = Sock} = State) ->
     [$^ ||
        send(Pckt, Sock),
        fmap(State#state{socket = _})
     ].
  
  
  