presto-main/src/main/java/io/prestosql/transaction/InMemoryTransactionManager.java/InMemoryTransactionManager/getConnectorTransaction
class InMemoryTransactionManager:    @Override
    public ConnectorTransactionHandle getConnectorTransaction(TransactionId transactionId, CatalogName catalogName)
    {
        return getCatalogMetadata(transactionId, catalogName).getTransactionHandleFor(catalogName);
    }