presto-orc/src/main/java/io/prestosql/orc/metadata/OrcType.java/OrcType/createRootOrcType
class OrcType:    public static ColumnMetadata<OrcType> createRootOrcType(List<String> fieldNames, List<Type> fieldTypes)
    {
        return new ColumnMetadata<>(createOrcRowType(0, fieldNames, fieldTypes));
    }