anchor.diff:      if B =:= max -> delta(BPrev, BList,
                             A, ARest,
                             BAFull,
  -                          [{gm, A, APrev, delta_next(BList, Before)} | Grows],
  +                          [{gm, A, {APrev, A}, delta_next(BList, Before)} | Grows],
                             Shrinks);
          A =:= max -> delta(B, BRest,
                             APrev, AList,
  
positive.code: ring_entry_test() ->
      (fun () ->
        C = create([{a, 1}, {b, 2}], ?MODULE, 1),
        ?assertEqual(2, length(C#cring.ring)),
        ?assertEqual(2, C#cring.addr_num),
        H = hd(C#cring.ring),
        [Ha] = hash_addr(a, 1),
        [Hb] = hash_addr(b, 1),
        case Ha < Hb of
  
negative.code:     ok.
  
  delta_check(Before, After, _ExpectGrows, _ExpectShrinks) ->
      {Grows, Shrinks} = delta(Before, After),
  case false of
  true ->
      ?debugVal("------"),
      ?debugVal(Before),
      ?debugVal(After),
      % ?debugVal(ExpectGrows),
      ?debugVal(Grows),
      ?debugVal(Shrinks),
      % ?assertEqual(ExpectGrows, Grows),
      % ?assertEqual(ExpectShrinks, Shrinks),
  ok;
  false -> ok
  end,
      ok.
  
  delta(Before, After) ->
  