*/
fun interface Authenticator {
  /**
   * Returns a request that includes a credential to satisfy an authentication challenge in
   * [response]. Returns null if the challenge cannot be satisfied.
   *
   * 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

        concurrentCallCapacity += connection.allocationLimit
      }

      // The policy was satisfied by existing connections, don't run again
      if (concurrentCallCapacity >= state.policy.minimumConcurrentCalls) return -1L
    }

    // If we got here then the policy was not satisfied -- open a connection!
    try {
      val connection = exchangeFinderFactory(this, state.address, PoolConnectionUser).find()

   *    has since been closed by the server.
   *  * A client timeout (HTTP 408).
   *  * A authorization challenge (HTTP 401 and 407) that is satisfied by the [Authenticator].
   *  * A retryable server failure (HTTP 503 with a `Retry-After: 0` response header).
   *  * A misdirected request (HTTP 421) on a coalesced connection.
   */
  open fun isOneShot(): Boolean = false

    if (strategy == ResumePriority.AfterOtherTasks && otherTasksStarted) {
      return yieldUntil(strategy, condition)
    }
  }

  private enum class ResumePriority {
    /** Resumes as soon as the condition is satisfied. */
    BeforeOtherTasks,

    /** Resumes after the already-enqueued tasks. */
    AfterEnqueuedTasks,

    /** Resumes after all other tasks, including tasks enqueued while yielding. */
    AfterOtherTasks,

      service.execute(barrierTask); // submit directly to the service
      // the barrier task runs after the error task so we know that the error has been observed by
      // SequentialExecutor by the time the barrier is satisfied
      barrier.await(1, SECONDS);
      executor.execute(barrierTask);
      // timeout means the second task wasn't even tried
      barrier.await(1, SECONDS);
    } finally {
      service.shutdown();
    }

            unverifiedHandshake.peerCertificates,
            address.url.host,
          )
        }
      this.handshake = handshake

      // Check that the certificate pinner is satisfied by the certificates presented.
      certificatePinner.check(address.url.host) {
        handshake.peerCertificates.map { it as X509Certificate }
      }

      // Success! Save the handshake and the ALPN protocol.

        }
        return CacheStrategy(null, builder.build())
      }

      // Find a condition to add to the request. If the condition is satisfied, the response body
      // will not be transmitted.
      val conditionName: String
      val conditionValue: String?
      when {
        etag != null -> {
          conditionName = "If-None-Match"

  /**
   * Prepare for a potential trip through all of this call's network interceptors. This prepares to
   * find an exchange to carry the request.
   *
   * Note that an exchange will not be needed if the request is satisfied by the cache.
   *
   * @param newRoutePlanner true if this is not a retry and new routing can be performed.
   */
  fun enterNetworkInterceptorExchange(
    request: Request,
    newRoutePlanner: Boolean,

    withLock {
      val oldLimit = allocationLimit
      allocationLimit = settings.getMaxConcurrentStreams()

      if (allocationLimit < oldLimit) {
        // We might need new connections to keep policies satisfied
        connectionPool.scheduleOpener(route.address)
      } else if (allocationLimit > oldLimit) {
        // We might no longer need some connections
        connectionPool.scheduleCloser()
      }
    }
  }

 *
 * This cache limits the number of bytes that it will store on the filesystem. When the number of
 * stored bytes exceeds the limit, the cache will remove entries in the background until the limit
 * is satisfied. The limit is not strict: the cache may temporarily exceed it while waiting for
 * files to be deleted. The limit does not include filesystem overhead or the cache journal so