anchor.diff:  stop_child(Ref) ->
       case diameter_reg:match(?TRANSPORT_KEY(Ref)) of
           [{_, Pid}] ->  %% tell the transport-specific child to die
  -            Pid ! {?MODULE, stop};
  +            Pid ! stop;
           [] ->          %% already removed/dead
               ok
       end.
  
positive.code: handle_call(state, _, State) ->
      {reply, State, State};
  
  handle_call(uptime, _, #state{id = Time} = State) ->
      {reply, diameter_lib:now_diff(Time), State};
  
  handle_call(Req, From, State) ->
      ?UNEXPECTED([Req, From]),
  
negative.code:               ?FAILURE(Reason) -> {error, Reason}
            end,
      proc_lib:init_ack({ok, self(), Res}),
      loop(Res).
  
  %% loop/1
  
  loop({ok, _}) ->
      gen_server:enter_loop(?MODULE, [], #state{role = transport});
  
  loop({error, _}) ->
      ok.  %% die
  
  %%% ----------------------------------------------------------
  %%% # handle_call/2
  