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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 update(self):
 """ Update connection information of all nodes in this cluster. It happens, for example, that public ip's are not available immediately, therefore calling this method might help. """

        for node in self.get_all_nodes():
            try:
                node.update_ips()

                # If we previously did not have a preferred_ip or the
                # preferred_ip is not in the current list, then try to connect
                # to one of the node ips and update the preferred_ip.
                if node.ips and \
                        not (node.preferred_ip and \
                                         node.preferred_ip in node.ips):
                    node.connect()
            except InstanceError as ex:
                log.warning("Ignoring error updating information on node %s: %s",
                            node, ex)
        self.repository.save_or_update(self)