def unregister_placeholder(self, placeholder):
        placeholder_name = placeholder.name
        if placeholder_name not in self.placeholders:
            raise PlaceholderNotRegistered(
                'The placeholder {!r} is not registered'.format(placeholder)
            )
        del self.placeholders[placeholder_name]
Tests defacl ch on multiple buckets.
dataset/ETHPy150Open ellmetha/django-precise-bbcode/precise_bbcode/placeholder_pool.py/PlaceholderPool.unregister_placeholder--crossover with--dataset/ETHPy150Open GoogleCloudPlatform/gsutil/gslib/tests/test_defacl.py/TestDefacl.testChangeMultipleBuckets