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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 subintf_real_ip_check_gw_port(self, gw_port, ip_addr, netmask):
 """ checks running-cfg derived ip_addr and netmask against neutron-db gw_port """

        if gw_port is not None:
            found = False
            for i in range(len(gw_port['fixed_ips'])):
                target_ip = gw_port['fixed_ips'][i]['ip_address']
                if ip_addr == target_ip:
                    found = True
                    break
            if found is False:
                LOG.info("Subintf real IP is incorrect, deleting")
                return False
            subnet_id = gw_port['fixed_ips'][i]['subnet_id']
            subnet = next(
                sn for sn in gw_port['subnets'] if sn['id'] == subnet_id)
            target_net = netaddr.IPNetwork(subnet['cidr'])
            if netmask != str(target_net.netmask):
                LOG.info("Subintf has incorrect netmask, deleting")
                return False

            return True

        return False