code: public static ClassAssertion createClassAssertion(OClass ce, ObjectConstant object) throws InconsistentOntologyException {
          if (ce.isTop())
              return null;
          if (ce.isBottom())
              throw new InconsistentOntologyException();
  
          return new ClassAssertionImpl(ce, object);
      }
docs: Creates a class assertion
  <p>
  ClassAssertion := 'ClassAssertion' '(' axiomAnnotations Class Individual ')'
  <p>
  Implements rule [C4]:
  - ignore (return null) if the class is top
  - inconsistency if the class is bot