presto-main/src/main/java/io/prestosql/transaction/InMemoryTransactionManager.java/InMemoryTransactionManager/removeTransactionMetadataAsFuture
class InMemoryTransactionManager:    private ListenableFuture<TransactionMetadata> removeTransactionMetadataAsFuture(TransactionId transactionId)
    {
        TransactionMetadata transactionMetadata = transactions.remove(transactionId);
        if (transactionMetadata == null) {
            return immediateFailedFuture(new NotInTransactionException(transactionId));
        }
        return immediateFuture(transactionMetadata);
    }