/**
 * An immutable representation of a host and port.
 *
 * <p>Example usage:
 *
 * {@snippet :
 * HostAndPort hp =
 *     HostAndPort.fromString("[2001:db8::1]")
 *         .withDefaultPort(80)
 *         .requireBracketsForIPv6();
 * hp.getHost();  // returns "2001:db8::1"
 * hp.getPort();  // returns 80
 * hp.toString(); // returns "[2001:db8::1]:80"
 * }
 *