def initial(self, request, *args, **kwargs):
        """
        Custom initial method:
            * ensure node exists and store it in an instance attribute
            * change queryset to return only links of current node
        """
        super(NodeLinkList, self).initial(request, *args, **kwargs)
        # ensure node exists
        try:
            self.node = Node.objects.published()\
                                    .accessible_to(request.user)\
                                    .get(slug=self.kwargs.get('slug', None))
        except Node.DoesNotExist:
            raise Http404(_('Node not found.'))
        # check permissions on node (for link creation)
        self.check_object_permissions(request, self.node)
        # return only links of current node
        self.queryset = Link.objects.select_related('node_a', 'node_b')\
                                    .accessible_to(self.request.user)\
                                    .filter(Q(node_a_id=self.node.id) |
                                            Q(node_b_id=self.node.id))