assertThrows(
        IllegalArgumentException.class,
        () -> InetAddresses.forString("1180::b059:65f4:e877:c40%eth9"));
  }

  public void testToAddrStringIPv4() {
    // Don't need to test IPv4 much; it just calls getHostAddress().
    assertThat(InetAddresses.toAddrString(InetAddresses.forString("1.2.3.4"))).isEqualTo("1.2.3.4");
  }