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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def example_list(a, args):
 """ list topics and cluster metadata """


    if len(args) == 0:
        what = "all"
    else:
        what = args[0]

    md = a.list_topics(timeout=10)

    print("Cluster {} metadata (response from broker {}):".format(md.cluster_id, md.orig_broker_name))

    if what in ("all", "brokers"):
        print(" {} brokers:".format(len(md.brokers)))
        for b in iter(md.brokers.values()):
            if b.id == md.controller_id:
                print("  {}  (controller)".format(b))
            else:
                print("  {}".format(b))

    if what not in ("all", "topics"):
        return

    print(" {} topics:".format(len(md.topics)))
    for t in iter(md.topics.values()):
        if t.error is not None:
            errstr = ": {}".format(t.error)
        else:
            errstr = ""

        print("  \"{}\" with {} partition(s){}".format(t, len(t.partitions), errstr))

        for p in iter(t.partitions.values()):
            if p.error is not None:
                errstr = ": {}".format(p.error)
            else:
                errstr = ""

            print("    partition {} leader: {}, replicas: {}, isrs: {}".format(
                p.id, p.leader, p.replicas, p.isrs, errstr))