private Iterable<Concept> getRangesConcepts(OWLOntology o, OWLObjectProperty objectProperty) {
    String uri = objectProperty.getIRI().toString();
    if (objectProperty.getRanges(o).size() == 0) {
      throw new LumifyException("Invalid number of range properties on " + uri);
    }

    List<Concept> ranges = new ArrayList<Concept>();
    for (OWLClassExpression rangeClassExpr : objectProperty.getRanges(o)) {
      OWLClass rangeClass = rangeClassExpr.asOWLClass();
      String rangeClassUri = rangeClass.getIRI().toString();
      Concept ontologyClass = getConceptByIRI(rangeClassUri);
      checkNotNull(ontologyClass, "Could not find class with uri: " + rangeClassUri);
      ranges.add(ontologyClass);
    }
    return ranges;
  }