def METHOD_NAME(self):
    super().METHOD_NAME()
    self.existing_submission_lock = SubmissionGradingLock.objects.create(
        submission_uuid=self.locked_submission_uuid,
        owner_id=self.user_id,
        created_at=datetime.now(tz=timezone.utc)
    )
    self.expired_submission_lock = SubmissionGradingLock.objects.create(
        submission_uuid=self.expired_locked_submission_uuid,
        owner_id=self.user_id,
        created_at=datetime.now(tz=timezone.utc) - (SubmissionGradingLock.TIMEOUT + timedelta(hours=1))
    )