public static Criterion matchEthSrc(MacAddress mac) {
        return new EthCriterion(mac, Type.ETH_SRC);
    }
@Test
    public void testMatchEthSrcMethod() {
        Criterion matchEthSrc = Criteria.matchEthSrc(mac1);
        EthCriterion ethCriterion =
                checkAndConvert(matchEthSrc,
                                Criterion.Type.ETH_SRC,
                                EthCriterion.class);
        assertThat(ethCriterion.mac(), is(mac1));
    }