Is the object cached for too long, so it should be redownloaded?

        See :attr:`.DB_MAX_WAIT_TIME` and :attr:`.DB_CACHE_TIME` for details.

        Returns:
            bool: True if it is.

def is_old(self):
        """
        Is the object cached for too long, so it should be redownloaded?

        See :attr:`.DB_MAX_WAIT_TIME` and :attr:`.DB_CACHE_TIME` for details.

        Returns:
            bool: True if it is.
        """
        if not self.processing_started_ts:
            return True

        if self.processing_ended_ts:
            return self.processing_ended_ts + DB_CACHE_TIME < time.time()

        # in case that processing started, but didn't ended in
        # DB_MAX_WAIT_TIME
        expected_end_ts = self.creation_ts + DB_MAX_WAIT_TIME
        if expected_end_ts < time.time():
            logger.error("Prosessing timeouted and properites were not set!")

        return expected_end_ts < time.time()