# import pickle
        #
        # with open('BankEUR.io', 'rb') as f:
        #     data = pickle.load(f)
        #
        # self._delete_all_obj()
        # log.info(self._get_all_objects())
        # for i in data:
        #     self._insert_obj(i)
        #
        # log.info(self._get_all_objects())

        # log.info(self._get_all_objects())
        # all_ = self._get_all_objects()
        # for one in all_:
        #     self._update_obj_by_id(_id=one['_id'], data={'week': float(one['week'])})
        # log.info(self._get_all_objects())

        # log.info(self._get_all_objects())
        # self._update_all(data={'YEAR': 1, 'MONTH': 1, 'DAY': 1, 'HOUR': 1})
        # log.info(self._get_all_objects())

        log.info(letter)
        # log.info(self._get_spec([{'$group': {'_id': {'day': {'$dayOfYear': '$time'}}, letter: {'$push': '${}'.format(letter)}, 'date': {'$push': '$time'}}}]))
        log.info(self._get_spec([{'$group': {'_id': None, letter: {'$push': {'$convert': {'input': '${}'.format(letter), 'to': "decimal"}}}, 'date': {'$push': '$time'}}}]))
        return self._get_spec([{'$group': {'_id': None, letter: {'$push': '${}'.format(letter)}, 'date': {'$push': '$time'}}}])