public EntryWriter launchEntryWriter(SequenceFile.Writer writer, int capacity) {
    final EntryWriter ew = new EntryWriter(writer, capacity);
    ew.start();
    return ew;
  }
@Test
  public void testCreateInvalidWriter() throws Throwable {
    intercept(NullPointerException.class, () ->
        entryFileIO.launchEntryWriter(null, 1));
  }