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