public VplsConfig vplsFromIface(String iface) {
        for (VplsConfig vpls : vplss()) {
            if (vpls.isAttached(iface)) {
                return vpls;
            }
        }
        return null;
    }
@Test
    public void getVplsFromInterface() {
        assertNotNull("VPLS not found", vplsAppConfig.vplsFromIface(IF1));
        assertNull("VPLS unexpectedly found",
                   vplsAppConfig.vplsFromIface(IF_NON_EXIST));
    }