code: def import_tags(self, tag_nodes):
          
          self.write_out(self.style.STEP('- Importing tags\n'))
          for tag_node in tag_nodes:
              tag_name = tag_node.find(
                  '{%s}tag_slug' % WP_NS).text[:50]
              self.write_out('> %s... ' % tag_name)
              Tag.objects.get_or_create(name=tag_name)
              self.write_out(self.style.ITEM('OK\n'))
docs: Import all the tags form 'wp:tag' nodes,
          because tags in 'item' nodes are not necessarily
          all the tags, then use only the nicename, because it's like
          a slug and the true tag name may be not valid for url usage.