anchor.diff:          false -> DefaultVal;
           X -> element(2, X)
       end.
  +
  +-spec trace_fwd({trace, pid(), call | return_to, mfa()}, pid()) -> pid().
  +trace_fwd({trace, Pid, call, {Mod, Fun, Params}}, TopPid) ->
  +    TopPid ! {trace, Pid, {Mod, Fun, length(Params)}},
  +    TopPid;
  +trace_fwd({trace, Pid, return_to, {Mod, Fun, Arity}}, TopPid) ->
  +    TopPid ! {trace, Pid, {Mod, Fun, Arity}},
  +    TopPid.
  +
  
positive.code: usage_inspect() ->
      io:format(
        "~n"
        " (q)uit, (e)val expr, (g)arb-coll."
        %% ", exclude (t)op itself" %% undocumented feature for top development
        "~n sort by: (c)pu usage~n").
  
  -spec on(comm:message(), state()) -> state().
  
  on({enable_sampling, Val}, State) -> set_sampling(State, Val);
  on({enable_output, Val}, State)   -> set_output(State, Val);
  on({sort_by, Type}, State)        -> set_sort_by(State, Type);
  on({toggle_exclude_self}, State)  -> toggle_exclude_self(State);
  
negative.code:                (WallClock rem (60*60)) rem 60
                ]),
      IdlePlotDataEntry = lists:keyfind({Pid, not_running}, 1, PlotData),
      Idle = case IdlePlotDataEntry of
          false -> 0.0;
          _ -> element(4, IdlePlotDataEntry)
      end,
      io:format("Pid: ~p, ~6.2f% run, ~6.2f% idle~n",
                [ Pid, 100.0 - Idle, Idle ]),
      io:format("Name: ~p",
  