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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 run_command(self):
 """replica_unavailability command, checks number of replicas not available for communication over all brokers in the Kafka cluster."""

        fetch_unavailable_brokers = True
        result = get_topic_partition_with_error(
            self.cluster_config,
            REPLICA_NOT_AVAILABLE_ERROR,
            fetch_unavailable_brokers=fetch_unavailable_brokers,
        )
        if fetch_unavailable_brokers:
            replica_unavailability, unavailable_brokers = result
        else:
            replica_unavailability = result

        errcode = status_code.OK if not replica_unavailability else status_code.CRITICAL
        out = _prepare_output(replica_unavailability, unavailable_brokers, self.args.verbose)
        return errcode, out