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

        nodes = []
        nodes.append(NavigationNode(_('Tags'), reverse('zinnia:tag_list'),
                                    'tags'))
        for tag in tags_published():
            nodes.append(NavigationNode(tag.name,
                                        reverse('zinnia:tag_detail',
                                                args=[tag.name]),
                                        tag.pk, 'tags'))
        return nodes