public static Options options() {
    return new Options("/tmp", 100, SorterType.HADOOP);
  }
@Test
  public void testNegativeMemory() {
    thrown.expect(IllegalArgumentException.class);
    thrown.expectMessage("memoryMB must be greater than zero");
    BufferedExternalSorter.Options options =
        BufferedExternalSorter.options().withTempLocation(getTmpLocation().toString());
    options.withMemoryMB(-1);
  }