presto-main/src/main/java/io/prestosql/connector/system/jdbc/FilterUtil.java/FilterUtil/tablePrefix
class FilterUtil:    public static QualifiedTablePrefix tablePrefix(String catalog, Optional<String> schema, Optional<String> table)
    {
        QualifiedTablePrefix prefix = new QualifiedTablePrefix(catalog);
        if (schema.isPresent()) {
            prefix = new QualifiedTablePrefix(catalog, schema.get());
            if (table.isPresent()) {
                prefix = new QualifiedTablePrefix(catalog, schema.get(), table.get());
            }
        }
        return prefix;
    }