@DataProvider(name = "sampleToString")
  Object[][] provider_sampleToString() {

    return new Object[][] { { 2008, 1, "2008-01" }, { 2008, 12, "2008-12" }, { 7, 5, "0007-05" }, { 0, 5, "0000-05" },
        { -1, 1, "-0001-01" }, };
  }

  @Test(dataProvider = "sampleToString", groups = { "tck" }