* transient query params, or has a canonical URL possibly for a CDN.
     *
     * Note that POST requests will not be sent to the server if this URL is set
     * and matches a cached response.
     */
    fun cacheUrlOverride(cacheUrlOverride: HttpUrl?) =
      apply {
        this.cacheUrlOverride = cacheUrlOverride
      }

    open fun build(): Request = Request(this)
  }

 *  Fix: Recover gracefully when a cached response is corrupted on disk.

 *  Fix: Don't leak file handles when a cache disk write fails.

 *  Fix: Don't hang when the public suffix database cannot be loaded. We had a bug where a failure
    reading the public suffix database would cause subsequent reads to hang when they should have
    crashed.

  internal const val B0_MASK_OPCODE = 15

  /** Flag in the opcode which indicates a control frame. */
  internal const val OPCODE_FLAG_CONTROL = 8

  /**
   * Byte 1 flag for whether the payload data is masked.
   *
   * If this flag is set, the next four
   * bytes represent the mask key. These bytes appear after any additional bytes specified by [B1_MASK_LENGTH].
   */
  internal const val B1_FLAG_MASK = 128

  /**

 * Can adjust Call timeouts using withConnectTimeout, withReadTimeout, withWriteTimeout.

**Network Interceptors**

 * Able to operate on intermediate responses like redirects and retries.
 * Not invoked for cached responses that short-circuit the network.
 * Observe the data just as it will be transmitted over the network.
 * Access to the `Connection` that carries the request.

### Rewriting Requests

     * concurrently, returning once any connection connects successfully.
     *
     * This implements Happy Eyeballs ([RFC 6555][rfc_6555]), balancing connect latency vs.
     * wasted resources.
     *
     * Defaults to enabled, call with [fastFallback] = false to revert to 4.x behaviour.
     *
     * [rfc_6555]: https://datatracker.ietf.org/doc/html/rfc6555
     */

     * first initiated.
     */
    private var sentRequestMillis = 0L

    /**
     * Extension header set by OkHttp specifying the timestamp when the cached HTTP response was
     * first received.
     */
    private var receivedResponseMillis = 0L

    /** Etag of the cached response. */
    private var etag: String? = null

    /** Age of the cached response. */

    assertThat(response.code).isEqualTo(expectedResponseCode)

    // Exhaust the content stream.
    response.body.string()
    val cached = cacheGet(cache, request)
    if (shouldWriteToCache) {
      assertThat(cached).isNotNull()
      cached!!.body.close()
    } else {
      assertThat(cached).isNull()
    }
    server.shutdown() // tearDown() isn't sufficient; this test starts multiple servers
  }

   */
  open fun cacheMiss(call: Call) {
  }

  /**
   * Invoked when a response will be served from the cache or network based on validating the
   * cached Response freshness. Will be followed by cacheHit or cacheMiss after the network
   * Response is available.
   *
   * This event will only be received when a Cache is configured for the client.
   */

      } catch (e: IOException) {
        logger.fine("$this connection from ${raw.inetAddress} failed: $e")
      } catch (e: Exception) {
        logger.log(Level.SEVERE, "$this connection from ${raw.inetAddress} crashed", e)
      }
    }
  }

  internal inner class SocketHandler(private val raw: Socket) {
    private var sequenceNumber = 0

    @Throws(Exception::class)
    fun handle() {

        } catch (_: IOException) {
          // Nothing useful to do here. We failed to remove from the cache. Most likely that's
          // because we couldn't update the journal, but the cached entry will still be gone.
        } finally {
          this.removeSnapshot = null
        }
      }
    }
  }

  /** A snapshot of the values for an entry. */