def METHOD_NAME(
    self, add_access, clean_up, detach_disk, destroy
):
    mommy.make(
        'Snapshot',
        volume=self.export
    )
    mommy.make(
        'Snapshot',
        instance=self.instance,
        volume=self.export,
        purge_at=datetime.now()
    )
    self.assertTrue(purge_unused_exports())
    add_access.assert_not_called()
    clean_up.assert_not_called()
    detach_disk.assert_not_called()
    destroy.assert_not_called()