anchor.diff:  
   %% ===================================================================
   %% gen_server callbacks
  -
  +-spec init({string(), ets:tab()}) -> {ok, state()}.
   init({Root, DeletedAges}) ->
       % Ensure only one gc process is running at a time.  We don't use a
       % named process to implement uniqueness so that our message queue
  
positive.code: handle_call(dbg_get_state, _, S) ->
      {reply, S, S}.
  
  handle_cast({gc_status, From}, #state{phase = P} = S) when is_pid(From) ->
      From ! {ok, P},
      {noreply, S};
  
negative.code:     gen_server:cast(self(), start),
      {ok, State}.
  
  -type is_orphan_msg() :: {is_orphan, object_type(), object_name(),
                            node(), volume_name()}.
  -spec handle_call(is_orphan_msg(), from(), state()) -> {reply, boolean(), state()};
                   (dbg_state_msg(), from(), state()) -> {reply, state(), state()}.
  handle_call({is_orphan, Type, ObjName, Node, Vol}, _, S) ->
      S1 = S#state{last_response_time = now()},
      {reply, check_is_orphan(S, Type, ObjName, Node, Vol), S1};
  