@Test
public void testAgeMergerDate() {

    AgeMerger merger = new AgeMerger();
    
    Number expected = 20.0;
    
    Calendar cal = Calendar.getInstance();
    cal.add(Calendar.YEAR, -1* expected.intValue());
    
    Number result = merger.mergeObjects(cal.getTime(), null);
    
    assertEquals("should be the same age", expected.intValue(), result.intValue());
}