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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 create(cls, name, ipv4_network=None, ipv6_network=None, comment=None):
 """ Create the network element :param str name: Name of element :param str ipv4_network: network cidr (optional if ipv6) :param str ipv6_network: network cidr (optional if ipv4) :param str comment: comment (optional) :raises CreateElementFailed: element creation failed with reason :return: instance with meta :rtype: Network .. note:: Either an ipv4_network or ipv6_network must be specified """

        ipv4_network = ipv4_network if ipv4_network else None
        ipv6_network = ipv6_network if ipv6_network else None
        json = {'name': name,
                'ipv4_network': ipv4_network,
                'ipv6_network': ipv6_network,
                'comment': comment}

        return ElementCreator(cls, json)