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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_nodes(self, request):
 """ Return menu's node for authors """

        nodes = []
        nodes.append(NavigationNode(_('Authors'),
                                    reverse('zinnia:author_list'),
                                    'authors'))
        for author in Author.published.all():
            nodes.append(NavigationNode(author.__str__(),
                                        author.get_absolute_url(),
                                        author.pk, 'authors'))
        return nodes