OWLClassExpression descB = df.getOWLObjectSomeValuesFrom(prop, clsB);
Set<OWLClassExpression> classExpressions = new HashSet<>();
classExpressions.add(descA);
classExpressions.add(descB);
OWLAxiom ax = df.getOWLDisjointClassesAxiom(classExpressions);
m.applyChange(new AddAxiom(ontA, ax));
OWLOntology ontB = roundTrip(ontA, new RDFXMLDocumentFormat());
assertTrue(ontB.getAxioms().contains(ax));
}