presto-raptor-legacy/src/main/java/io/prestosql/plugin/raptor/legacy/RaptorMetadata.java/RaptorMetadata/hiddenColumn
class RaptorMetadata:    private static ColumnMetadata hiddenColumn(String name, Type type)
    {
        return ColumnMetadata.builder()
                .setName(name)
                .setType(type)
                .setHidden(true)
                .build();
    }