presto-accumulo/src/main/java/io/prestosql/plugin/accumulo/AccumuloConnector.java/AccumuloConnector/commit
class AccumuloConnector:    @Override
    public void commit(ConnectorTransactionHandle transactionHandle)
    {
        checkArgument(transactions.remove(transactionHandle) != null, "no such transaction: %s", transactionHandle);
    }