@Override
    public OpenstackVtapNetwork updateVtapNetwork(OpenstackVtapNetwork description) {
        checkNotNull(description, VTAP_DESC_NULL, "vtapNetwork");
        return store.updateVtapNetwork(VTAP_NETWORK_KEY, description);
    }
@Test(expected = NullPointerException.class)
    public void testUpdateNullVtapNetwork() {
        target.updateVtapNetwork(null);
    }