anchor.diff:  
   start_link() ->
       gen_statem:start_link(?MODULE, [], []).
  +
  +append(_Node, _LogId, _LogRecord) ->
  +    {ok, {0, node}}.
  +
  +asyn_append(_Node, _LogId, _LogRecord, ReplyTo) ->
  +    case ReplyTo of
  +        ignore -> ok;
  +        {_, _, Pid} -> gen_fsm:send_event(Pid, {ok, 0})
  +    end,
  +    ok.
   
   %% @doc Initialize the state.
   init([]) ->
  
positive.code: -include("antidote.hrl").
  
  %% API
  -export([start_link/0]).
  
  %% Callbacks
  -export([init/1,
           callback_mode/0,
           execute_op/4,
           execute_op/3,
           code_change/4,
           append/3,
           asyn_append/4,
           terminate/3]).
  
  -export([get_my_dc_id/0,
           get_clock_of_dc/2,
           get_preflist_from_key/1,
           read_data_item/5,
           generate_downstream_op/7,
           get_key_partition/1,
           get_logid_from_key/1,
           update_data_item/5,
           prepare/2,
           value/1,
           set_clock_of_dc/3,
           abort/2,
           commit/3,
           single_commit/2,
           get_stable_snapshot/0,
           inc/2,
           inc/1,
           dec/1]).
  
  -record(state, {
          key :: atom()}).
  
negative.code:     gen_fsm:send_event(From, ack_abort),
      {stop, normal, State}.
  
  %%%===================================================================
  %%% statem CALLBACK FUNCTIONS
  %%%=====================================================================
  
  callback_mode() -> state_functions.
  
  code_change(_OldVsn, StateName, State, _Extra) -> {ok, StateName, State}.
  
  terminate(_Reason, _SN, _SD) -> ok.
  
  