def search(self, regex):
        try:
            spec = {'$or': [{'data.content'    : {'$regex': regex, '$options': 'im'}},
                            {'data.description': {'$regex': regex, '$options': 'im'}}]}
            fields = {'_id': 0}
            cur = self.db.docs.find(spec, fields)
        except Exception as e:
            raise DatabaseException(e)
        return [Document(**row) for row in cur]
async def pre_process(self, message, data):
        """
        context language variable will be set each time when update from 'process_update_types' comes
        value is the result of 'get_user_language' method
        """
        self.context_lang.set(await self.get_user_language(obj=message))