@Test
public void testEquals() {

    LOG.info("testEquals");
    final Tuple<Double, String> s = Tuple.create(x1, x2);
    final Tuple<Double, String> t = Tuple.create(y1, y2);
    Assert.assertTrue(x.equals(s));
    Assert.assertTrue(y.equals(t));
    Assert.assertFalse(x.equals(t));
    Assert.assertFalse(y.equals(s));
}