@Override
    public Subnet subnet(String subnetId) {
        checkArgument(!Strings.isNullOrEmpty(subnetId), ERR_NULL_SUBNET_ID);
        return osNetworkStore.subnet(subnetId);
    }
@Test
    public void testGetSubnetById() {
        createBasicNetworks();
        assertTrue("Subnet did not match", target.subnet(SUBNET_ID) != null);
        assertTrue("Subnet did not match", target.subnet(UNKNOWN_ID) == null);
    }