def ipv4_private(self, network=False, address_class=None):
        """
        Returns a private IPv4.

        :param network: Network address
        :param address_class: IPv4 address class (a, b, or c)
        :returns: Private IPv4
        """
        # compute private networks from given class
        supernet = _IPv4Constants._network_classes[
            address_class or self.ipv4_network_class()
        ]

        private_networks = [
            subnet for subnet in _IPv4Constants._private_networks
            if subnet.overlaps(supernet)
        ]

        # exclude special networks
        private_networks = self._exclude_ipv4_networks(
            private_networks,
            _IPv4Constants._excluded_networks,
        )

        # choose random private network from the list
        private_network = self.generator.random.choice(private_networks)

        return self._random_ipv4_address_from_subnet(private_network, network)
Returns a private IPv4.

        :param network: Network address
        :param address_class: IPv4 address class (a, b, or c)
        :returns: Private IPv4