def test_verifier(self):
factory = self.element_factory
c = factory.create(UML.Class)
p = factory.create(UML.Property)
c.ownedAttribute = p
assert not orphan_references(factory)
# Now create a separate item, not part of the factory:
m = UML.Comment(id="acd123")
m.annotatedElement = c
assert m in c.ownedComment
assert orphan_references(factory)
