anchor.diff:      ?assertEqual(20, ReadResult2),
       lager:info("read_pncounter_old_value_not_in_ets_test OK").
   
  +%% Add number 1 to 5 to an orset and remember the snapshot.
  +%% Then we add numbers 6 to 20 and read the old value not in the ets.
  +read_orset_old_value_not_in_ets_test(Nodes) ->
  +    lager:info("read_pncounter_old_value_not_in_ets_test started"),
  +    FirstNode = hd(Nodes),
  +    Type = crdt_orset,
  +    Key = read_orset_old_val,
  +    add_elements_starting_from(FirstNode, Key, 5, 0),
  +    {ok, {_, [ReadResult], _}} = rpc:call(FirstNode, antidote, clocksi_execute_tx,
  +        [[{read, {Key, Type}}]]),
  +    ?assertEqual([1, 2, 3, 4, 5], ReadResult),
  +    {ok, TxId} = rpc:call(FirstNode, antidote, clocksi_istart_tx, []),
  +    add_elements_starting_from(FirstNode, Key, 15, 5),
  +    {ok, ReadResult1} = rpc:call(FirstNode,
  +        antidote, clocksi_iread, [TxId, Key, Type]),
  +    %% old read value contains elements 1 to 5
  +    ?assertEqual([1, 2, 3, 4, 5], ReadResult1),
  +    {ok, {_, [ReadResult2], _}} = rpc:call(FirstNode, antidote, clocksi_execute_tx,
  +        [[{read, {Key, Type}}]]),
  +    %% most recent read vale contains elements 1 to 20
  +    ?assertEqual([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
  +        13, 14, 15, 16, 17, 18, 19, 20], ReadResult2),
  +    lager:info("read_pncounter_old_value_not_in_ets_test OK").
  +
   %% Auxiliary method to increment a counter N times.
   increment_counter(_FirstNode, _Key, 0) ->
       ok;
  
positive.code:     WriteResult = rpc:call(FirstNode, antidote, clocksi_execute_tx,
          [[{update, {Key, crdt_pncounter, {increment, a}}}]]),
      ?assertMatch({ok, _}, WriteResult),
      increment_counter(FirstNode, Key, N - 1).
negative.code:     lager:info("Vnodes are started up"),
  
      lager:info("Nodes: ~p", [Nodes]),
      read_pncounter_initial_value_not_in_ets_test(Nodes),
      read_pncounter_old_value_not_in_ets_test(Nodes),
      read_orset_old_value_not_in_ets_test(Nodes),
      pass.
  
  %% First we remember the initial time of the counter (with value 0).
  