assertEquals("::1", HostAndPort.fromString("[::1]:80").requireBracketsForIPv6().getHost());
    // Non-bracketed non-IPv6 works fine.
    assertEquals("x", HostAndPort.fromString("x").requireBracketsForIPv6().getHost());
    assertEquals("x", HostAndPort.fromString("x:80").requireBracketsForIPv6().getHost());

    // Non-bracketed IPv6 fails.
    try {

    assertEquals("::1", HostAndPort.fromString("[::1]:80").requireBracketsForIPv6().getHost());
    // Non-bracketed non-IPv6 works fine.
    assertEquals("x", HostAndPort.fromString("x").requireBracketsForIPv6().getHost());
    assertEquals("x", HostAndPort.fromString("x:80").requireBracketsForIPv6().getHost());

    // Non-bracketed IPv6 fails.
    try {

    // IPv6 literals.
    HostAndPort parsedHost = HostAndPort.fromString(specifier);
    Preconditions.checkArgument(!parsedHost.hasPort());
    String host = parsedHost.getHost();

    // Try to interpret the specifier as an IP address. Note we build
    // the address rather than using the .is* methods because we want to
    // use InetAddresses.toUriString to convert the result to a string in

 *     .requireBracketsForIPv6();
 * hp.getHost();   // returns "2001:db8::1"
 * hp.getPort();   // returns 80
 * hp.toString();  // returns "[2001:db8::1]:80"
 * </pre>
 *
 * <p>Here are some examples of recognized formats:
 *
 * <ul>
 *   <li>example.com
 *   <li>example.com:80
 *   <li>192.0.2.1
 *   <li>192.0.2.1:80
 *   <li>[2001:db8::1] - {@link #getHost()} omits brackets