presto-main/src/main/java/io/prestosql/transaction/InMemoryTransactionManager.java/ConnectorTransactionMetadata/ConnectorTransactionMetadata
class ConnectorTransactionMetadata:            public ConnectorTransactionMetadata(CatalogName catalogName, Connector connector, ConnectorTransactionHandle transactionHandle)
            {
                this.catalogName = requireNonNull(catalogName, "catalogName is null");
                this.connector = requireNonNull(connector, "connector is null");
                this.transactionHandle = requireNonNull(transactionHandle, "transactionHandle is null");
                this.connectorMetadata = connector.getMetadata(transactionHandle);
            }