anchor.diff:                     not_yet_implemented(),
                      ?TT(?MINS(5)),
                      Send = fun(Sock, Data) -> socket:send(Sock, Data) end,
  -                   Recv = fun(Sock)       -> socket:recv(Sock)       end,
  +                   Recv = fun(Sock, Sz)   -> socket:recv(Sock, Sz) end,
                      InitState = #{domain => inet6,
                                    send   => Send, % Send function
                                    recv   => Recv  % Receive function
  
positive.code:         {error, Reason} ->
              exit({failed_closing, Reason})
      end;
  tpp_tcp_client_msg_exchange_loop(Sock, Send, Recv, Msg, 
                                   Num, N, Sent, Received, Start) ->
      d("[~w,~w] try send", [Num,N]),
      case Send(Sock, Msg) of
          ok ->
              d("[~w,~w] sent - no try recv", [Num,N]),
              case Recv(Sock) of
                  {ok, NewMsg} ->
                      tpp_tcp_client_msg_exchange_loop(Sock, Send, Recv,
                                                       NewMsg, Num, N+1,
                                                       Sent+size(Msg), 
                                                       Received+size(NewMsg), 
                                                       Start);
                  {error, RReason} ->
                      ?SEV_EPRINT("recv (~w of ~w): ~p", [N, Num, RReason]),
  
negative.code:                    %% not_yet_implemented(),
                     ?TT(?MINS(5)),
                     Send = fun(Sock, Data) -> socket:send(Sock, Data) end,
                     Recv = fun(Sock, Sz)   -> socket:recv(Sock, Sz) end,
                     InitState = #{domain => inet,
                                   send   => Send, % Send function
                                   recv   => Recv  % Receive function
  