Get and discard all pending updates before first poll of the bot
        :return: total updates skipped

def __skip_updates(self):
        """
        Get and discard all pending updates before first poll of the bot
        :return: total updates skipped
        """
        total = 0
        updates = self.get_updates(offset=self.last_update_id, timeout=1)
        while updates:
            total += len(updates)
            for update in updates:
                if update.update_id > self.last_update_id:
                    self.last_update_id = update.update_id
            updates = self.get_updates(offset=self.last_update_id + 1, timeout=1)
        return total