anchor.diff:      ?BACKEND_CONNECTOR_FSM:start_link(read, {Key, From}),
       {noreply, S0};
   
  -handle_command({update, Key, Value, Clock}, _From, S0=#state{max_ts=MaxTS0, seq=Seq0}) ->
  +handle_command({update, Key, Value, Clock}, _From, S0=#state{max_ts=MaxTS0, seq=Seq0, partition=Partition}) ->
       PhysicalClock = saturn_utilities:now_microsec(),
       TimeStamp = max(Clock, max(PhysicalClock, MaxTS0)),
       Seq1=Seq0+1,
       ?BACKEND_CONNECTOR_FSM:start_link(update, {Key, Value, TimeStamp, Seq1}),
  -    {reply, {ok, TimeStamp}, S0#state{max_ts=TimeStamp, seq=Seq1}};
  +    {reply, {ok, TimeStamp}, S0#state{max_ts=TimeStamp, seq=Seq1, last_label={Key, TimeStamp, {Partition, node()}}}};
   
   handle_command({update_completed, Key, Value, TimeStamp, Seq}, _From, S0=#state{partition=Partition, myid=MyId}) ->
       Label = {Key, TimeStamp, {Partition, node()}},
  
positive.code:     saturn_leaf_producer:partition_heartbeat(MyId, Partition, Clock, Seq1),
      riak_core_vnode:send_command_after(?HEARTBEAT_FREQ, {heartbeat, MyId}),
      {noreply, S0#state{myid=MyId, seq=Seq1}};
  
  handle_command(Message, _Sender, State) ->
      ?PRINT({unhandled_command, Message}),
  
negative.code: init([Partition]) ->
      {ok, #state{partition=Partition,
                  max_ts=0,
                  last_label=none,
                  seq=0}}.
  
  %% @doc The table holding the prepared transactions is shared with concurrent
  %%      readers, so they can safely check if a key they are reading is being updated.
  