### Question:
DefaultOrdinalReferenceSystem extends DefaultTemporalReferenceSystem implements OrdinalReferenceSystem { @Override @XmlElement(name = "component", required = true) public Collection<OrdinalEra> getComponents() { return ordinalEraSequence; } DefaultOrdinalReferenceSystem(Map<String, ?> properties, Collection<OrdinalEra> ordinalEraSequence); private  DefaultOrdinalReferenceSystem();  DefaultOrdinalReferenceSystem(final OrdinalReferenceSystem object); static DefaultOrdinalReferenceSystem castOrCopy(final OrdinalReferenceSystem object); @Override @XmlElement(name = "component", required = true) Collection<OrdinalEra> getComponents(); @Override boolean equals(Object object, ComparisonMode mode); @Override String toString();  }### Answer:
@Test public void testGetOrdinalEraSequence() { Collection<OrdinalEra> result = (Collection<OrdinalEra>) ordinalReferenceSystem1.getComponents(); assertEquals(ordinalReferenceSystem2.getComponents(), result); }