@Test
public void addInPlace() {

    final JdbcHighWaterMark left = new JdbcHighWaterMark();
    left.accumulate(1L);
    final JdbcHighWaterMark right = new JdbcHighWaterMark();
    right.accumulate(2L);
    final JdbcHighWaterMark result = new JdbcHighWaterMarkAccumulableParam().addInPlace(left, right);
    Assert.assertEquals(new Long(2L), result.getValue());
    Assert.assertEquals(left, result);
}