* or response.
 *
 * Implementations of this interface throw [IOException] to signal connectivity failures. This
 * includes both natural exceptions such as unreachable servers, as well as synthetic exceptions
 * when responses are of an unexpected type or cannot be decoded.
 *
 * Other exception types cancel the current call:
 *

     */
    @JvmField val minimumConcurrentCalls: Int = 0,
    /** How long to wait to retry pre-emptive connection attempts that fail. */
    @JvmField val backoffDelayMillis: Long = 60 * 1000,
    /** How much jitter to introduce in connection retry backoff delays */
    @JvmField val backoffJitterMillis: Int = 100,
  )

   *
   * The route is best effort, it currently may not always be provided even when logically
   * available. It may also not be provided when an authenticator is re-used manually in an
   * application interceptor, such as when implementing client-specific retries.
   */
  @Throws(IOException::class)
  fun authenticate(
    route: Route?,
    response: Response,
  ): Request?

  companion object {

 *  Fix: Retry automatically when incorrectly sharing a connection among multiple hostnames. OkHttp
    shares connections when hosts share both IP addresses and certificates, such as `squareup.com`
    and `www.squareup.com`. If a server refuses such sharing it will return HTTP 421 and OkHttp will
    automatically retry on an unshared connection.
 *  Fix: Don't crash if a TLS tunnel's response body is truncated.

A single HTTP call may require follow-up requests to be made to handle authentication challenges, redirects, and HTTP-layer timeouts. In such cases multiple connections, requests, and responses may be attempted. Follow-ups are another reason a single call may trigger multiple events of the same type.

![Events Diagram](../assets/images/******@****.***)

  private const val TMAX = 26
  private const val SKEW = 38
  private const val DAMP = 700
  private const val INITIAL_BIAS = 72
  private const val INITIAL_N = 0x80

  /**
   * Returns null if any label is oversized so much that the encoder cannot encode it without
   * integer overflow. This will not return null for labels that fit within the DNS size
   * limits.
   */
  fun encode(string: String): String? {
    var pos = 0

   * and response body streams; otherwise resources may be leaked.
   *
   * This method is safe to be called concurrently, but provides limited guarantees. If a transport
   * layer connection has been established (such as a HTTP/2 stream) that is terminated. Otherwise
   * if a socket connection is being established, that is terminated.
   */
  override fun cancel() {
    if (canceled) return // Already canceled.

  /** Timestamp when `allocations.size()` reached zero. Also assigned upon initial connection. */
  var idleAtNs = Long.MAX_VALUE

  /**
   * Returns true if this is an HTTP/2 connection. Such connections can be used in multiple HTTP
   * requests simultaneously.
   */
  internal val isMultiplexed: Boolean
    get() = http2Connection != null

    //
    //  * Several characters are forbidden and must throw exceptions if used.
    //  * They don't use percent escaping at all.
    //  * They use punycode for internationalization.
    //  * URI is much more strict than HttpUrl or URL on what's accepted.
    //
    // HttpUrl is quite lenient with what characters it accepts. In particular, characters like '{'

   * be received. The default implementation returns an empty response. Mischievous implementations
   * can return other values to test HTTP edge cases, such as unhappy socket policies or throttled
   * request bodies.
   */
  open fun peek(): MockResponse {
    return MockResponse(socketPolicy = KeepOpen)
  }

  /**