var addresses1 []Address
	if err := DB.Model(&person).Association("Addresses").Find(&addresses1); err != nil || len(addresses1) != 2 {
		t.Fatalf("Failed to find address, got error %v, length: %v", err, len(addresses1))
	}

	if err := DB.Model(&person).Association("Addresses").Delete(&person.Addresses[0]); err != nil {
		t.Fatalf("Failed to delete address, got error %v", err)
	}

	if len(person.Addresses) != 1 {

/**
 * Implementation of HappyEyeballs Sorting Addresses.
 *
 * The current implementation does not address any of:
 *  - Async DNS split by IP class
 *  - Stateful handling of connectivity results
 *  - The prioritisation of addresses
 *
 * https://datatracker.ietf.org/doc/html/rfc8305#section-4
 */
internal fun reorderForHappyEyeballs(addresses: List<InetAddress>): List<InetAddress> {
  if (addresses.size < 2) {
    return addresses
  }

   * an IPv4 address or not.
   *
   * <p>IPv6 addresses are <b>coerced</b> to IPv4 addresses before being converted to integers.
   *
   * <p>As long as there are applications that assume that all IP addresses are IPv4 addresses and
   * can therefore be converted safely to integers (for whatever purpose) this function can be used
   * to handle IPv6 addresses as well until the application is suitably fixed.
   *

import okhttp3.Dns.Companion.SYSTEM

/**
 * A domain name service that resolves IP addresses for host names. Most applications will use the
 * [system DNS service][SYSTEM], which is the default. Some applications may provide their own
 * implementation to use a different DNS server, to prefer IPv6 addresses, to prefer IPv4 addresses,
 * or to force a specific known IP address.
 *

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> {
    val addresses = Dns.SYSTEM.lookup(hostname)
    return listOf(addresses[0], addresses[0])
  }

	"github.com/minio/minio/internal/logger"
	xnet "github.com/minio/pkg/v3/net"
)

var (
	// IPv4 addresses of localhost.
	localIP4 = mustGetLocalIP4()

	// IPv6 addresses of localhost.
	localIP6 = mustGetLocalIP6()

	// List of all local loopback addresses.
	localLoopbacks = mustGetLocalLoopbacks()
)

// mustSplitHostPort is a wrapper to net.SplitHostPort() where error is assumed to be a fatal.

   * an IPv4 address or not.
   *
   * <p>IPv6 addresses are <b>coerced</b> to IPv4 addresses before being converted to integers.
   *
   * <p>As long as there are applications that assume that all IP addresses are IPv4 addresses and
   * can therefore be converted safely to integers (for whatever purpose) this function can be used
   * to handle IPv6 addresses as well until the application is suitably fixed.
   *

  private var nextAddress = 0xff000064L // 255.0.0.100 in IPv4; ::ff00:64 in IPv6.

  /** Sets the results for `hostname`.  */
  operator fun set(
    hostname: String,
    addresses: List<InetAddress>,
  ): FakeDns {
    hostAddresses[hostname] = addresses
    return this
  }

  /** Clears the results for `hostname`.  */
  fun clear(hostname: String): FakeDns {
    hostAddresses.remove(hostname)
    return this
  }

They're also concrete: each URL identifies a specific path (like `/square/okhttp`) and query (like `?q=sharks&lang=en`). Each webserver hosts many URLs.

### [Addresses](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-address/)

Addresses specify a webserver (like `github.com`) and all of the **static** configuration necessary to connect to that server: the port number, HTTPS settings, and preferred network protocols (like HTTP/2).

			// the 'for=' capture, which we ignore. In the case of multiple IP
			// addresses (for=8.8.8.8, 8.8.4.4, 172.16.1.20 is valid) we only
			// extract the first, which should be the client IP.
			if match := forRegex.FindStringSubmatch(fwd); len(match) > 1 {
				// IPv6 addresses in Forwarded headers are quoted-strings. We strip
				// these quotes.
				addr = strings.Trim(match[1], `"`)
			}
		}