@Test
public void testEquals() {

    Pair pair = new Pair("lhs", "rhs");
    Assert.assertTrue(pair.equals(pair));
    Assert.assertTrue(pair.equals(new Pair("lhs", "rhs")));
    Assert.assertFalse(pair.equals(null));
    Assert.assertFalse(pair.equals(new Pair(null, "rhs")));
    Assert.assertFalse(pair.equals(new Pair("lhs", null)));
}