public Set<INamedConcept> getConcepts() {

      Set<OWLClass> clazzs = m_delegate.getOWLClasses();
      Set<INamedConcept> iClazzs = null;

      if (s_log.isDebugEnabled()) s_log.debug("get concept of node: " + this.toString());

      if (clazzs != null) {
        iClazzs = new HashSet<INamedConcept>();
        for (OWLClass clazz : clazzs) {
          INamedConcept concept = new NamedConcept(clazz.getURI(), m_onto);
          concept.setDelegate(clazz);
          iClazzs.add(concept);
          if (s_log.isDebugEnabled()) s_log.debug("concept found: " + ((OWLClass) clazz).getURI());
        }
      }

      return iClazzs;
    }
  public ISchemaNode getNode(INamedConcept clazz) {

    return new XHierarchicalSchemaNode(
        m_delegate.getNodeFor(KAON2Manager.factory().owlClass(clazz.getUri())));
  }