human
Solve the following python programming problem given the following code:
@snippet
def topic_subscription(client, to_delete):
assistant
#Here is the Python program you requested.

    """Create subscriptions to a topic.
    """
    TOPIC_NAME = ('topic_subscription-%d' % (_millis(),))
    SUB_DEFAULTS = ('topic_subscription-defaults-%d' % (_millis(),))
    SUB_ACK90 = ('topic_subscription-ack90-%d' % (_millis(),))
    topic = client.topic(TOPIC_NAME)
    topic.create()
    to_delete.append(topic)
    sub_defaults = topic.subscription(SUB_DEFAULTS)
    sub_defaults.create()
    to_delete.append(sub_defaults)
    expected_names = set()
    expected_names.add(sub_defaults.full_name)
    sub_ack90 = topic.subscription(SUB_ACK90, ack_deadline=90)
    sub_ack90.create()
    to_delete.append(sub_ack90)
    expected_names.add(sub_ack90.full_name)
    sub_names = set()
    def do_something_with(sub):
        sub_names.add(sub.full_name)
    for subscription in topic.list_subscriptions():
        do_something_with(subscription)
    assert sub_names.issuperset(expected_names)