@Test
public void testGetMemberDueDate() {

    assertEquals(zms.getMemberDueDate(100, null), Timestamp.fromMillis(100));
    assertEquals(zms.getMemberDueDate(100, Timestamp.fromMillis(50)), Timestamp.fromMillis(50));
    assertEquals(zms.getMemberDueDate(100, Timestamp.fromMillis(150)), Timestamp.fromMillis(100));
}