@Test
public void testDataTypeDetection() throws Exception {

  InputStream stream = new FileInputStream(new File("../data/fixed_width_cars_test.txt"));
  FixedWidthReadOptions options =
      FixedWidthReadOptions.builder(stream)
          .header(true)
          .columnSpecs(car_fields_specs)
          .padding('_')
          .systemLineEnding()
          .sample(false)
          .locale(Locale.getDefault())
          .minimizeColumnSizes()
          .build();
  Reader reader = new FileReader("../data/fixed_width_missing_values.txt");
  ColumnType[] columnTypes = new FixedWidthReader().detectColumnTypes(reader, options);
  assertArrayEquals(car_types, columnTypes);
}