code: @Override
      public Node<OWLObjectPropertyExpression> getEquivalentObjectProperties(
              OWLObjectPropertyExpression pe)
              throws InconsistentOntologyException, FreshEntitiesException,
              ReasonerInterruptedException, TimeOutException {
          return new OWLObjectPropertyNode();
      }
docs: Gets the set of <a href="#spe">simplified object property expressions</a>
  that are equivalent to the specified object property expression with
  respect to the set of reasoner axioms. The properties are returned as a
  {@link Node}.
  
  @param pe
  The object property expression whose equivalent properties are
  to be retrieved.
  @return A node containing the <a href="#spe">simplified object property
  expressions</a> such that for each <a href="#spe">simplified
  object property expression</a>, <code>P</code>, in the node, the
  set of reasoner axioms entails
  <code>EquivalentObjectProperties(pe P)</code>. </p> If
  <code>pe</code> is a <a href="#spe">simplified object property
  expression</a> then <code>pe</code> will be contained in the
  node. </p> If <code>pe</code> is unsatisfiable with respect to
  the set of reasoner axioms then the node representing and
  containing <code>owl:bottomObjectProperty</code>, i.e. the bottom
  node, will be returned. </p> If <code>pe</code> is equivalent to
  <code>owl:topObjectProperty</code> with respect to the set of
  reasoner axioms then the node representing and containing
  <code>owl:topObjectProperty</code>, i.e. the top node, will be
  returned </p>.
  
  @throws InconsistentOntologyException
  if the imports closure of the root ontology is inconsistent
  @throws FreshEntitiesException
  if the signature of the object property expression is not
  contained within the signature of the imports closure of the
  root ontology and the undeclared entity policy of this
  reasoner is set to {@link FreshEntityPolicy#DISALLOW}.
  @throws ReasonerInterruptedException
  if the reasoning process was interrupted for any particular
  reason (for example if reasoning was cancelled by a client
  process)
  @throws TimeOutException
  if the reasoner timed out during a basic reasoning operation.
  See {@link #getTimeOut()}.