@Test
public void testExtendsSpan() {

nal DateTime t = new DateTime(2013, 12, 11, 8, 0, 0);
nal DateTime t2 = new DateTime(2013, 12, 11, 13, 0, 0);
    final SpanImpl newSpan = new SpanImpl(Period.ONE_HOUR, t, t2);
nal DateTime t3 = new DateTime(2013, 12, 11, 12, 0, 0);
nal DateTime t4 = new DateTime(2013, 12, 11, 16, 0, 0);
    final SpanImpl newSpan2 = new SpanImpl(Period.ONE_HOUR, t3, t4);
    assertTrue(newSpan2.extendsSpan(newSpan) && newSpan.extendsSpan(newSpan2));
}