@Override
    public String toString() {
        final StringBuilder builder = new StringBuilder(2 * 6 + 5);
        for (final byte b : this.address) {
            if (builder.length() > 0) {
                builder.append(':');
            }
            builder.append(String.format("%02X", b & 0xFF));
        }
        return builder.toString();
    }
@Test
    public void testToString() throws Exception {
        assertEquals(MAC_ONOS_STR, MAC_ONOS.toString());
    }