def METHOD_NAME(env):
    # The subscribe client blocks all messages by default, the subscribe method
    # allows messages with a prefix that matches the topic_filter. Therefore an
    # empty string allows all messages through.
    env.client1.subscribe(topic_filter=b"")
    env.client2.subscribe(topic_filter=b"")
    # The ZMQ Subscribe client takes a bit longer to actually connect, no
    # connection results in dropped messages There is no way to verify the
    # connection currently so we add a small delay after start.
    time.sleep(1)