def get_item(self, item_id):
     return Contract.query(self.session).get(item_id)
 def accumulation_revert(self, db_session):
     for item in Contract.query(db_session).filter_by(created_at_block=self.block.id):
         db_session.delete(item)
 def get_query(self):
     return Contract.query(self.session).order_by(
         Contract.created_at_block.desc())