presto-blackhole/src/main/java/io/prestosql/plugin/blackhole/BlackHoleMetadata.java/BlackHoleMetadata/listTableColumns
class BlackHoleMetadata:    @Override
    public Map<SchemaTableName, List<ColumnMetadata>> listTableColumns(ConnectorSession session, SchemaTablePrefix prefix)
    {
        return tables.values().stream()
                .filter(table -> prefix.matches(table.toSchemaTableName()))
                .collect(toMap(BlackHoleTableHandle::toSchemaTableName, handle -> handle.toTableMetadata().getColumns()));
    }