anchor.diff:           api_a_sendmsg_and_recvmsg_tcp4/1,
            api_a_recvfrom_cancel_udp4/1,
            api_a_recvmsg_cancel_udp4/1,
  -         %% api_a_accept_cancel_tcp4/1,
  +         api_a_accept_cancel_tcp4/1,
            %% api_a_recv_cancel_tcp4/1,
            %% api_a_recvmsg_cancel_tcp4/1,
   
  
positive.code: api_a_recvfrom_cancel_udp4(doc) ->
      [];
  api_a_recvfrom_cancel_udp4(_Config) when is_list(_Config) ->
      ?TT(?SECS(5)),
      tc_try(api_a_recvfrom_cancel_udp4,
             fun() ->
                     Recv = fun(Sock) ->
  
negative.code:          #{desc => "try recv request (with nowait, expect select)",
             cmd  => fun(#{sock := Sock, recv := Recv} = State) ->
                             case Recv(Sock) of
                                 {ok, {select, _, _} = SelectInfo} ->
                                     {ok, State#{recv_select_info => SelectInfo}};
                                 {ok, X} ->
                                     {error, {unexpected_select_info, X}};
  