presto-blackhole/src/main/java/io/prestosql/plugin/blackhole/BlackHoleMetadata.java/BlackHoleMetadata/listTables
class BlackHoleMetadata:    @Override
    public List<SchemaTableName> listTables(ConnectorSession session, Optional<String> schemaName)
    {
        return tables.values().stream()
                .filter(table -> !schemaName.isPresent() || table.getSchemaName().equals(schemaName.get()))
                .map(BlackHoleTableHandle::toSchemaTableName)
                .collect(toList());
    }