@Test
  public void testSignedInt128IntIntIntInt() {
    assertEquals(((long) 11) << 32L | 23L,
        new SignedInt128(23, 11, 0, 0).longValue());
  }
Testcases for {@link SignedInt128}

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