### Question:
DefaultCalendarEra extends AbstractIdentifiedObject implements CalendarEra { public void setJulianReference(final JulianDate julianReference) { ArgumentChecks.ensureNonNull("julianReference", julianReference); this.julianReference = julianReference; } DefaultCalendarEra(Map<String, ?> properties,
            final CalendarDate referenceDate, final JulianDate julianReference, final Period epochOfUse); private  DefaultCalendarEra(); private  DefaultCalendarEra(final CalendarEra object); static DefaultCalendarEra castOrCopy(final CalendarEra object); @Override @XmlElement(name = "referenceEvent", required = true) InternationalString getReferenceEvent(); @Override CalendarDate getReferenceDate(); @Override JulianDate getJulianReference(); @Override @XmlElement(name = "epochOfUse", required = true) Period getEpochOfUse(); Collection<Calendar> getDatingSystem(); void setReferenceEvent(final InternationalString referenceEvent); void setReferenceDate(final CalendarDate referenceDate); void setJulianReference(final JulianDate julianReference); void setEpochOfUse(final Period epochOfUse); void setDatingSystem(final Collection<Calendar> newValues); @Override boolean equals(Object object, ComparisonMode mode); @Override String toString();  }### Answer:
@Test public void testSetJulianReference() { JulianDate result = calendarEra1.getJulianReference(); ((DefaultCalendarEra)calendarEra1).setJulianReference(FACTORY.createJulianDate(frame1, IndeterminateValue.UNKNOWN, 785410)); assertFalse(calendarEra1.getJulianReference().equals(result)); }