public void removeSubscription(Topic topic) {
        subscriptions.remove(new Subscription(data.clientId(), topic, MqttSubscriptionOption.onlyFromQos(MqttQoS.EXACTLY_ONCE)));
    }
@Test
    public void testRemoveSubscription() {
        client.addSubscriptions(Arrays.asList(new Subscription(CLIENT_ID, new Topic("topic/one"), MqttSubscriptionOption.onlyFromQos(MqttQoS.AT_MOST_ONCE))));
        Assertions.assertThat(client.getSubscriptions()).hasSize(1);
        client.addSubscriptions(Arrays.asList(new Subscription(CLIENT_ID, new Topic("topic/one"), MqttSubscriptionOption.onlyFromQos(MqttQoS.EXACTLY_ONCE))));
        Assertions.assertThat(client.getSubscriptions()).hasSize(1);
        client.removeSubscription(new Topic("topic/one"));
        Assertions.assertThat(client.getSubscriptions()).isEmpty();
    }