Get task meta for task by ``task_id``.

        :keyword exception_retry_count: How many times to retry by
            transaction rollback on exception. This could theoretically
            happen in a race condition if another worker is trying to
            create the same task. The default is to retry once.

def get_task(self, task_id):
        """Get task meta for task by ``task_id``.

        :keyword exception_retry_count: How many times to retry by
            transaction rollback on exception. This could theoretically
            happen in a race condition if another worker is trying to
            create the same task. The default is to retry once.

        """
        try:
            return self.get(task_id=task_id)
        except self.model.DoesNotExist:
            if self._last_id == task_id:
                self.warn_if_repeatable_read()
            self._last_id = task_id
            return self.model(task_id=task_id)