def get_post_by_id(self, post_id):
        raise NotImplementedError("This method needs to be implemented by the "
                                  "inheriting class")
Should the related object be hidden?
dataset/ETHPy150Open gouthambs/Flask-Blogging/flask_blogging/storage.py/Storage.get_post_by_id--crossover with--dataset/ETHPy150Open cloudera/hue/desktop/core/ext-py/Django-1.6.10/django/db/models/fields/related.py/ManyToManyRel.is_hidden