anchor.diff:  %%          partition: the partition that the vnode is responsible for.
   %%          prepared_tx: a list of prepared transactions.
   %%          committed_tx: a list of committed transactions.
  -%%          waiting_fsms: a list of the read_fsms that are currently
  -%%              waiting for each tx to finish.
   %%          active_txs_per_key: a list of the active transactions that
   %%              have updated a key (but not yet finished).
   %%          write_set: a list of the write sets that the transactions
  
positive.code: %%      1. notify all read_fsms that are waiting for this transaction to finish
  %%      2. clean the state of the transaction. Namely:
  %%      a. ActiteTxsPerKey,
  %%      b. Waiting_Fsms,
  %%      c. PreparedTx
  %%
  clean_and_notify(TxId, Key, #state{active_txs_per_key=ActiveTxsPerKey,
                                     prepared_tx=PreparedTx,
  
negative.code: -record(state, {partition,
                  prepared_tx,
                  committed_tx,
                  active_txs_per_key,
                  write_set}).
  
  