anchor.diff:  %% API
   -export([ all_cfg_keys/0
           , get_api_vsns/1
  +        , get_endpoint/1
           , get_tcp_sock/1
           , init/4
           , loop/2
  
positive.code: handle_msg({From, get_api_vsns}, State, Debug) ->
    _ = reply(From, {ok, State#state.api_vsns}),
    ?MODULE:loop(State, Debug);
  handle_msg({From, get_tcp_sock}, State, Debug) ->
    _ = reply(From, {ok, State#state.sock}),
    ?MODULE:loop(State, Debug);
  
negative.code:         {ok, ?undef | kpro:vsn_ranges()} | {error, any()}.
  get_api_vsns(Pid) ->
    call(Pid, get_api_vsns).
  
  -spec get_endpoint(pid()) -> {ok, kpro:endpoint()} | {error, any()}.
  get_endpoint(Pid) ->
    call(Pid, get_endpoint).
  
  %% @hidden
  -spec get_tcp_sock(pid()) -> {ok, port()}.
  