anchor.diff:  -include("dmerkle.hrl").
   
   %% API
  --export([open/1, open/2, equals/2, get_tree/1, count/2, count_trace/2, update/3, delete/2, leaves/1, find/2, visualized_find/2, key_diff/2, close/1, scan_for_empty/1, swap_tree/2]).
  +-export([open/1, open/2, equals/2, get_tree/1, count/2, count_trace/2, update/3, updatea/3, delete/2, deletea/2, leaves/1, find/2, visualized_find/2, key_diff/2, close/1, scan_for_empty/1, swap_tree/2]).
   
   %% gen_server callbacks
   -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
  
positive.code: %% @doc Handling cast messages
  %% @end 
  %%--------------------------------------------------------------------
  handle_cast(close, Tree) ->
      {stop, shutdown, Tree}.
  
  
negative.code: 
  delete(Key, Tree) ->
    gen_server:call(Tree, {delete, Key}).
    
  deletea(Key, Tree) ->
    gen_server:cast(Tree, {delete, Key}).
  
  key_diff(TreeA, TreeB) ->
    gen_server:call(TreeA, {key_diff, TreeB}).
  