anchor.diff:  %% @type bkey()={bucket(),key()}
   %% @type value()=term().
   
  --export([new/3, ancestors/1, reconcile/2, increment_vclock/2, equal/2]).
  +-export([new/3, new/4, ancestors/1, reconcile/2, increment_vclock/2, equal/2]).
   -export([key/1, get_metadata/1, get_metadatas/1, get_values/1, get_value/1]).
   -export([vclock/1, update_value/2, update_metadata/2, bucket/1, value_count/1]).
   -export([get_update_metadata/1, get_update_value/1, get_contents/1]).
  
positive.code:     ?assertEqual(2, length(ND)),
      ?assert(lists:member(O0, ND)),
      ?assert(lists:member(O1, ND)).
  
negative.code: 
  -module(riak_object).
  -include_lib("eunit/include/eunit.hrl").
  -include("riak_kv_wm_raw.hrl").
  
  -record(r_content, {
            metadata :: dict(),
  