anchor.diff:  
   do_several_accepts_in_one_go(Config) ->
       ?P("create listen socket"),
  -    LS = case ?LISTEN(Config, 0,[]) of
  +    NumActors = 8,
  +    LS = case ?LISTEN(Config, 0, [{backlog, NumActors}]) of
                {ok, LSock} ->
                    LSock;
                {error, eaddrnotavail = Reason} ->
  
positive.code:          end,
      Parent = self(),
      {ok, PortNo} = inet:port(LS),
      F1 = fun() -> ?P("acceptor starting"),
                    Parent ! {accepted,self(),gen_tcp:accept(LS)}
           end,
      F2 = fun() -> ?P("connector starting"),
                    Parent ! {connected,self(),?CONNECT(Config, "localhost",PortNo,[])}
           end,
      Ns = lists:seq(1,8),
      ?P("start acceptors"),
      _  = [spawn(F1) || _ <- Ns],
      ?P("await accept timeouts"),
  
negative.code:     ?P("start connectors"),
      _  = [spawn(F2) || _ <- Ns],
      ?P("await accepts"),
      ok = ?EXPECT_ACCEPTS([{_,{ok,_}},{_,{ok,_}},{_,{ok,_}},{_,{ok,_}},{_,{ok,_}},{_,{ok,_}},{_,{ok,_}},{_,{ok,_}}],NumActors,15000),
      ?P("await connects"),
      ok = ?EXPECT_CONNECTS([{_,{ok,_}},{_,{ok,_}},{_,{ok,_}},{_,{ok,_}},{_,{ok,_}},{_,{ok,_}},{_,{ok,_}},{_,{ok,_}}],1000),
      ?P("done"),
  