public McastConfig setEgressVlan(VlanId vlanId) {
        if (vlanId == null) {
            object.remove(EGRESS_VLAN);
        } else {
            object.put(EGRESS_VLAN, vlanId.toString());
        }
        return this;
    }
@Test
    public void setEgressVlan() throws Exception {
        config.setEgressVlan(EGRESS_VLAN_2);

        VlanId egressVlan = config.egressVlan();
        assertNotNull("egressVlan should not be null", egressVlan);
        assertThat(egressVlan, is(EGRESS_VLAN_2));
    }