public String convert(Object o) {
    StringBuilder buf = new StringBuilder();
    Converter<Object> p = headTokenConverter;
    while (p != null) {
      buf.append(p.convert(o));
      p = p.getNext();
    }
    return buf.toString();
  }
@Test
  public void convertMultipleDates() {
    Calendar cal = Calendar.getInstance();
    cal.set(2003, 4, 20, 17, 55);
    FileNamePattern fnp = new FileNamePattern("foo-%d{yyyy.MM, aux}/%d{yyyy.MM.dd}.txt", context);
    assertEquals("foo-2003.05/2003.05.20.txt", fnp.convert(cal.getTime()));
  }