anchor.diff:    end, open(data_file(), 256), lists:seq(1,495)),
   TreeB = lists:foldl(fun(N, Tree) ->
       update(lists:concat(["key", N]), lists:concat(["value", N]), Tree)
  -  end, open("/Users/cliff/data/dmerkle1", 256), lists:seq(1,500)),
  +  end, open(data_file(1), 256), lists:seq(1,500)),
   error_logger:info_msg("rootA ~p~nrootB ~p~n", [TreeA#dmerkle.root, TreeB#dmerkle.root]),
   Diff = key_diff(TreeA, TreeB),
   Keys = lists:map(fun(N) -> lists:concat(["key", N]) end, lists:seq(496, 500)),
  
positive.code:   TreeA = lists:foldl(fun(N, Tree) ->
        update(lists:concat(["key", N]), lists:concat(["value", N]), Tree)
      end, open(data_file(), 256), lists:seq(1,500)),
    TreeB = open("/Users/cliff/data/dmerkle1", 256),
    500 = length(key_diff(TreeA, TreeB)).
    
  live_test_() ->
    {timeout, 120, [{?LINE, fun() ->
      TreeA = open("/Users/cliff/data/dmerkle410", 4096),
      TreeB = open("/Users/cliff/data/dmerkle42", 4096),
      KeyDiff = key_diff(TreeA, TreeB),
      error_logger:info_msg("key_diff: ~p~n", [KeyDiff]),
      LeavesA = leaves(TreeA),
  
negative.code:       update(lists:concat(["key"]), lists:concat(["value", N]), Tree)
      end, lists:foldl(fun(N, Tree) ->
          update(lists:concat(["key"]), lists:concat(["value", N]), Tree)
        end, open(data_file(1), 256), lists:seq(1,3000)), lists:seq(1, 3000)),
    % Diff = key_diff(TreeA, TreeB),
    % [] = Diff,
    1 = length(leaves(TreeB)).
  