code: protected Collection<String> getPropertyValues(final Property property) {
          final ExtendedIterator<Triple> iterator = graph.find(Node.ANY,
                                                               property.asNode(),
                                                               Node.ANY);
          final Set<String> set = new HashSet<>();
          while (iterator.hasNext()) {
              final Node object = iterator.next().getObject();
              if (object.isLiteral()) {
                  set.add(object.getLiteralValue().toString());
              } else if (object.isURI()) {
                  set.add(object.getURI().toString());
              } else {
                  set.add(object.toString());
              }
          }
          return set;
      }
docs: Return all the values of a property
  
  @param property The Property to get values for
  @return Collection of values