anchor.diff:  
   reset_prepared(_PreparedTx, [], _TxId, _Time, _ActiveTxs) ->
       ok;
  -reset_prepared(PreparedTx, [{Key, _Type, {_Op, _Actor}} | Rest], TxId, Time, ActiveTxs) ->
  +reset_prepared(PreparedTx, [{Key, _Type, _Update} | Rest], TxId, Time, ActiveTxs) ->
       %% Could do this more efficiently in case of multiple updates to the same key
       true = ets:insert(PreparedTx, {Key, [{TxId, Time} | dict:fetch(Key, ActiveTxs)]}),
       reset_prepared(PreparedTx, Rest, TxId, Time, ActiveTxs).
  
positive.code: 
  set_prepared(_PreparedTx, [], _TxId, _Time, Acc) ->
      Acc;
  set_prepared(PreparedTx, [{Key, _Type, {_Op, _Actor}} | Rest], TxId, Time, Acc) ->
      ActiveTxs = case ets:lookup(PreparedTx, Key) of
                      [] ->
                          [];
  
negative.code:     case certification_check(TxId, TxWriteSet, CommittedTx, PreparedTx) of
          true ->
              case TxWriteSet of
                  [{Key, _Type, _Update} | _] ->
                      Dict = set_prepared(PreparedTx, TxWriteSet, TxId, PrepareTime, dict:new()),
                      NewPrepare = now_microsec(dc_utilities:now()),
                      ok = reset_prepared(PreparedTx, TxWriteSet, TxId, NewPrepare, Dict),
  