anchor.diff:  %% and after each test case.
   
   chk() ->
  -    persistent_term:info().
  -
  -chk(Chk) ->
  -    Chk = persistent_term:info(),
  +    {persistent_term:info(), persistent_term:get()}.
  +
  +chk({Info, _Initial} = Chk) ->
  +    Info = persistent_term:info(),
       Key = {?MODULE,?FUNCTION_NAME},
  -    ok = persistent_term:put(Key, {term,Chk}),
  +    ok = persistent_term:put(Key, {term,Info}),
       Term = persistent_term:get(Key),
       true = persistent_term:erase(Key),
       chk_not_stuck(Term),
  +    [persistent_term:erase(K) || {K, _} <- pget(Chk)],
       ok.
   
   chk_not_stuck(Term) ->
  
positive.code:         _ ->
              ok
      end.
  
negative.code:             _ -> 1000
          end,
      spawn_link(fun() -> info_trapping_create(N) end),
      All = do_info_trapping(N, 0, Chk),
      N = info_trapping_check_result(lists:sort(All), 1),
      erlang:garbage_collect(),
      info_trapping_erase(N),
      chk(Chk).
  
  do_info_trapping(N, PrevMem, Chk) ->
      case info_info() of
          {M,Mem} when M >= N ->
              true = Mem >= PrevMem,
              All = [P || {{?MODULE,{info_trapping,_}},_}=P <- pget(Chk)],
              case length(All) of
                  N -> All;
                  _ -> do_info_trapping(N, PrevMem, Chk)
              end;
          {_,Mem} ->
              true = Mem >= PrevMem,
              receive after 1 -> ok end,
              do_info_trapping(N, Mem, Chk)
      end.
  
  info_trapping_create(0) ->
  