@Test
  public void testHashCode() {
    assertTrue(one.hashCode() != two.hashCode());
    assertTrue(zero.hashCode() != one.hashCode());
    assertTrue(zero.hashCode() != two.hashCode());

    assertTrue(one.hashCode() != negativeOne.hashCode());
    assertTrue(two.hashCode() != negativeTwo.hashCode());
    assertEquals(zero.hashCode(), new SignedInt128(-0).hashCode());

    assertEquals(zero.hashCode(), new SignedInt128(0).hashCode());
    assertEquals(one.hashCode(), new SignedInt128(1).hashCode());
    assertEquals(two.hashCode(), new SignedInt128(2).hashCode());
  }
Testcases for {@link SignedInt128}

This code was based on code from Microsoft PolyBase.
common/src/test/org/apache/hadoop/hive/common/type/TestSignedInt128.java