anchor.diff:               end
            end).
   
  +perhaps_trip_append_page(false, Res, _Page) ->
  +    Res;
  +perhaps_trip_append_page(true, {ok, LPN}, _Page) when LPN > 3 ->
  +    io:format(user, "TRIP: append_page\n", []),
  +    {ok, 3};
  +perhaps_trip_append_page(true, Else, _Page) ->
  +    Else.
  +
  +perhaps_trip_read_approx(false, Res, _LPN) ->
  +    Res;
  +perhaps_trip_read_approx(true, _Res, 3 = LPN) ->
  +    io:format(user, "TRIP: read_approx LPN ~p", [LPN]),
  +    <<"FAKE!">>;
  +perhaps_trip_read_approx(true, Res, _LPN) ->
  +    Res.
  +
  +perhaps_trip_scan_forward(false, Res, _EndLPN) ->
  +    Res;
  +perhaps_trip_scan_forward(true, _Res, 20) ->
  +    io:format(user, "TRIP: scan_forward\n", []),
  +    <<"magic number bingo, you are a winner">>;
  +perhaps_trip_scan_forward(true, Res, _EndLPN) ->
  +    Res.
  +
   -endif. % PULSE
   -endif. % TEST
   
  
positive.code:                           PidI = {self(), I},
                            event_logger:event(log_make_call(PidI, {read, LPN}),
                                               TS1),
                            Pm = read_result_mangle(P),
                            event_logger:event(log_make_result(PidI, Pm), TS2)
                        end || {{LPN, P}, I} <- PageIs],
                       Ps = [{LPN, read_result_mangle(P)} ||
  
negative.code:                        {ok, V2s} = orddict:find(LPN, Values),
                         NewVs = lists:umerge(lists:sort(V1s),
                                              lists:sort(V2s)),
                         %% Throw an exception (which is equivalent to a no-op)
                         %% if there are no differences: if we make multiples
                         %% of the exact same thing, stateful() will get confused.
                         false = NewVs == V1s,
                         {read, Pid, LPN, NewVs};
                    ({read, Pid, LPN, Vs}, {result, Pid, Pg}) ->
  