public McastConfig setIngressVlan(VlanId vlanId) {
        if (vlanId == null) {
            object.remove(INGRESS_VLAN);
        } else {
            object.put(INGRESS_VLAN, vlanId.toString());
        }
        return this;
    }
@Test
    public void setIngressVlan() throws Exception {
        config.setIngressVlan(INGRESS_VLAN_2);

        VlanId ingressVlan = config.ingressVlan();
        assertNotNull("ingressVlan should not be null", ingressVlan);
        assertThat(ingressVlan, is(INGRESS_VLAN_2));
    }