int freeIps(Node host) {
        if (host.type() == NodeType.host) {
            return allNodes.eventuallyUnusedIpAddressCount(host);
        }
        return host.ipConfig().pool().findUnusedIpAddresses(allNodes).size();
    }
@Test
    public void freeIPs() {
        assertEquals(2, capacity.freeIps(host1));
        assertEquals(1, capacity.freeIps(host2));
        assertEquals(1, capacity.freeIps(host3));
        assertEquals(0, capacity.freeIps(host4));
    }