#13 CalendarInterval.equals throws NPE

[Anonymous]

The unit below fails with a nullpointer exception. The equals method does not account for open-ended intervals:

import junit.framework.TestCase;
import com.domainlanguage.time.CalendarDate;
import com.domainlanguage.time.CalendarInterval;

public class CalendarIntervalTest extends TestCase {
public void testEquality() {
CalendarInterval i1 =
CalendarInterval.everFrom(CalendarDate.date(2008, 1, 1));
CalendarInterval i2 =
CalendarInterval.everFrom(CalendarDate.date(2008, 1, 1));

assertEquals("i1 & i2 are not equal", i1, i2);
}

}