presto-accumulo/src/main/java/io/prestosql/plugin/accumulo/AccumuloClient.java/AccumuloClient/getScanAuthorizations
class AccumuloClient:    private Authorizations getScanAuthorizations(ConnectorSession session, String schema,
            String table)
            throws AccumuloException, AccumuloSecurityException
    {
        String sessionScanUser = AccumuloSessionProperties.getScanUsername(session);
        if (sessionScanUser != null) {
            Authorizations scanAuths = connector.securityOperations().getUserAuthorizations(sessionScanUser);
            LOG.debug("Using session scan auths for user %s: %s", sessionScanUser, scanAuths);
            return scanAuths;
        }

        AccumuloTable accumuloTable = this.getTable(new SchemaTableName(schema, table));
        if (accumuloTable == null) {
            throw new TableNotFoundException(new SchemaTableName(schema, table));
        }

        Optional<String> strAuths = accumuloTable.getScanAuthorizations();
        if (strAuths.isPresent()) {
            Authorizations scanAuths = new Authorizations(Iterables.toArray(COMMA_SPLITTER.split(strAuths.get()), String.class));
            LOG.debug("scan_auths table property set, using: %s", scanAuths);
            return scanAuths;
        }

        LOG.debug("scan_auths table property not set, using connector auths: %s", this.auths);
        return this.auths;
    }