@Override
    public Set<Subnet> subnets() {
        return osNetworkStore.subnets();
    }
@Test
    public void testGetSubnetsByNetworkId() {
        createBasicNetworks();
        assertEquals("Subnet did not match", 1, target.subnets(NETWORK_ID).size());
        assertEquals("Subnet did not match", 0, target.subnets(UNKNOWN_ID).size());
    }