anchor.diff:                             end
                      end},
            #{desc => "order server to terminate",
  -           cmd  => fun(#{server := Server} = State) ->
  +           cmd  => fun(#{server := Server} = _State) ->
                              Server ! {terminate, self()},
                              ok
                      end},
  
positive.code:     end.
      
  
  sock_listen(Sock) ->
      sock_listen2(fun() -> socket:listen(Sock) end).
  
  sock_listen(Sock, BackLog) ->
      sock_listen2(fun() -> socket:listen(Sock, BackLog) end).
  
  sock_listen2(Listen) ->
      try Listen() of
          ok ->
              ok;
          {error, Reason} ->
              ?FAIL({listen, Reason})
      catch
          C:E:S ->
              ?FAIL({listen, C, E, S})
      end.
  
  
  sock_accept(LSock) ->
      try socket:accept(LSock) of
          {ok, Sock} ->
              Sock;
          {error, Reason} ->
              p("sock_accept -> error: ~p", [Reason]),
              ?FAIL({accept, Reason})
      catch
          C:E:S ->
              p("sock_accept -> failed: ~p, ~p, ~p", [C, E, S]),
              ?FAIL({accept, C, E, S})
      end.
  
  
  sock_close(Sock) ->
  
negative.code:     [];
  api_to_recvmsg_tcp4(_Config) when is_list(_Config) ->
      tc_begin(api_to_recvmsg_tcp4),
      Recv = fun(Sock) -> socket:recvmsg(Sock, 5000) end,
      InitState = #{domain => inet, recv => Recv},
      ok = api_to_receive_tcp(InitState),
      tc_end().
  
  
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  