anchor.diff:      Seedtree4_1 = seedtree_init(Fd4, RootPos4, 3),
       ?debugVal(Seedtree4_1),
       Seedtree4_2 = seedtree_insert_list(Seedtree4_1, Nodes4),
  -    {ok, ResultPos4} = seedtree_write(Fd4, Seedtree4_2, TargetTreeHeight4),
  +    {ok, Result4} = seedtree_write(Fd4, Seedtree4_2, TargetTreeHeight4),
  +    ?debugVal(Result4),
  +    {ok, ResultPos4} = write_parent(Fd4, Result4),
       ?debugVal(ResultPos4),
       {ok, Lookup4} = vtree:lookup(Fd4, ResultPos4, {0,0,1001,1001}),
       ?assertEqual(914, length(Lookup4)),
  +    LeafDepths4 = vtreestats:leaf_depths(Fd4, ResultPos4),
  +    ?assertEqual([5], LeafDepths4),
   
       % Test 1.5: adding new data with height=4 (seedtree height=1)
       TargetTreeNodeNum5 = 800,
  
positive.code:     end,
      ?debugVal(NewChildren3),
  
      % XXX vmx: it is implicitly expected that NewChildren3 doesn't
      %     contain a nested list, though this could happen if NewChildren
      %     is bigger than math:pow(?MAX_FILLED, 2).
  
  
      % Calculate the common MBR. The result is a tuple of the MBR and
  
negative.code: 
  
  % XXX vmx: rename to _test when it should be run again
  seedtree_write_single_test() ->
      % insert single new node
      TargetTreeNodeNum = 7,
      {ok, {Fd, {RootPos, TargetTreeHeight}}} = vtree_test:build_random_tree(
  