def save(self, *args, **kwargs):
        self.treewalk(save=False)
        super(KnowledgeCategory, self).save(*args, **kwargs)

# KnowledgeItem model
:reference: https://dev.twitter.com/rest/reference/post/lists/create
dataset/ETHPy150Open treeio/treeio/treeio/knowledge/models.py/KnowledgeCategory.save--crossover with--dataset/ETHPy150Open tweepy/tweepy/tweepy/api.py/API.create_list