* decimal digits and dots. This pattern matches strings like "a:.23" and "54" that are neither IP
 * addresses nor hostnames; they will be verified as IP addresses (which is a more strict
 * verification).
 */
private val VERIFY_AS_IP_ADDRESS = "([0-9a-fA-F]*:[0-9a-fA-F:.]*)|([\\d.]+)".toRegex()

/** Returns true if this string is not a host name and might be an IP address. */
fun String.canParseAsIpAddress(): Boolean = VERIFY_AS_IP_ADDRESS.matches(this)

There may be many routes for a single address. For example, a webserver that is hosted in multiple datacenters may yield multiple IP addresses in its DNS response.

   * be logged if the test fails.
   *
   * This client is also configured to be slightly more deterministic, returning a single IP
   * address for all hosts, regardless of the actual number of IP addresses reported by DNS.
   */
  fun newClient(): OkHttpClient {
    var client = testClient
    if (client == null) {
      client =
        initialClientBuilder()

     * Print the log.
     * @param message The message.
     */
    protected void printLog(final String message) {
        logger.info(message);
    }

    /**
     * Get the client IP.
     * @return The client IP.
     */
    protected String getClientIp() {
        return LaRequestUtil.getOptionalRequest().map(req -> ComponentUtil.getViewHelper().getClientIp(req)).orElse("-");
    }

    /**

### Bug or Regression

- EndpointSlice IP validation now matches Endpoints IP validation. ([#101084](https://github.com/kubernetes/kubernetes/pull/101084), [@robscott](https://github.com/robscott)) [SIG Apps and Network]

                buf.append(hostname);
            }
            final String ip = ia.getHostAddress();
            if (StringUtil.isNotBlank(ip)) {
                if (buf.length() > 0) {
                    buf.append(" : ");
                }
                buf.append(ip);
            }
        } catch (final Exception e) {
            // ignore
        }

    rather than the duration specified in the response's cache-control header.
 *  Fix: Verify certificate IP addresses in canonical form. When a server presents a TLS certificate
    containing an IP address we must match that address against the URL's IP address, even when the
    two addresses are encoded differently, such as `192.168.1.1` and `0::0:0:FFFF:C0A8:101`. Note

 *    "www.squareup.com".
 *
 *  * **A set of hostnames.** These are in the certificate's subject alternative name (SAN)
 *    extension. A subject alternative name is either a literal hostname (`squareup.com`), a literal
 *    IP address (`74.122.190.80`), or a hostname pattern (`*.api.squareup.com`).
 *
 *  * **A validity interval.** A certificate should not be used before its validity interval starts
 *    or after it ends.
 *

    // req_extensions=req_extensions
    // x509_extensions=x509_extensions
    // [distinguished_name]
    // [req_extensions]
    // [x509_extensions]
    // subjectAltName=IP:0:0:0:0:0:0:0:1,IP:2a03:2880:f003:c07:face:b00c::2,IP:0::5,IP:192.168.1.1
    //
    // $ openssl req -x509 -nodes -days 36500 -subj '/CN=foo.com' -config ./cert.cnf \
    //     -newkey rsa:512 -out cert.pem
    val session =
      session(

 * limitations under the License.
 */
package okhttp3.internal

import java.net.InetAddress
import okhttp3.Dns

/**
 * A network that always resolves two IP addresses per host. Use this when testing route selection
 * fallbacks to guarantee that a fallback address is available.
 */
class DoubleInetAddressDns : Dns {
  override fun lookup(hostname: String): List<InetAddress> {