// clear retained message and check that we don't receive it
connection.publish(TOPICA, "".getBytes(), QoS.AT_MOST_ONCE, true);
connection.subscribe(new Topic[]{new Topic(TOPICA, QoS.AT_LEAST_ONCE)});
msg = connection.receive(5000, TimeUnit.MILLISECONDS);
assertNull("Retained message not cleared for " + clientId, msg);
connection.unsubscribe(new String[]{"TopicA"});
// set retained message again and check
connection.publish(TOPICA, RETAIN.getBytes(), QoS.EXACTLY_ONCE, true);
connection.subscribe(new Topic[]{new Topic(TOPICA, QoS.AT_LEAST_ONCE)});
msg = connection.receive(5000, TimeUnit.MILLISECONDS);