* including dots after the first colon. It matches IPv4 addresses as strings containing only
 * 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()

    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.
 *  Fix: Don't track unusable routes beyond their usefulness. We had a bug where we could track

   * [requestBodyOpen], [responseBodyOpen], and [expectMoreExchanges].
   *
   * This will release the connection if it is still held.
   *
   * It will also notify the listener that the call completed; either successfully or
   * unsuccessfully.
   *
   * If the call was canceled or timed out, this will wrap [e] in an exception that provides that
   * additional context. Otherwise [e] is returned as-is.
   */

     *
     * In this case the bytes are immediately copied into [sink] and the number of bytes copied is
     * returned.
     *
     * If upstream would be selected but another thread is already reading upstream this will
     * block until that read completes. It is possible to time out while waiting for that.
     */
    @Throws(IOException::class)
    override fun read(
      sink: Buffer,
      byteCount: Long,
    ): Long {

        connectionPool.scheduleCloser()
      }
    }
  }

  override fun handshake(): Handshake? = handshake

  /** Track a bad route in the route database. Other routes will be attempted first. */
  internal fun connectFailed(
    client: OkHttpClient,
    failedRoute: Route,
    failure: IOException,
  ) {
    // Tell the proxy selector when we fail to connect on a fresh connection.

      Thread.currentThread().interrupt() // Retain interrupted status.
      throw InterruptedIOException()
    }
  }

  /**
   * The Okio timeout watchdog will call [timedOut] if the timeout is reached. In that case we close
   * the stream (asynchronously) which will notify the waiting thread.
   */
  internal inner class StreamTimeout : AsyncTimeout() {
    override fun timedOut() {
      closeLater(ErrorCode.CANCEL)

   * Response and normal event sequences will not be received.
   *
   * This event will only be received when a Cache is configured for the client.
   */
  open fun cacheHit(
    call: Call,
    response: Response,
  ) {
  }

  /**
   * Invoked when a response will be served from the network. The Response will be
   * available from normal event sequences.
   *

 * Clients call [get] to read a snapshot of an entry. The read will observe the value at the time
 * that [get] was called. Updates and removals after the call do not impact ongoing reads.
 *
 * This class is tolerant of some I/O errors. If files are missing from the filesystem, the
 * corresponding entries will be dropped from the cache. If an error occurs while writing a cache
 * value, the edit will fail silently. Callers should handle other problems by catching

   * was acquired, or null if no connection was acquired. The acquired connection will also be
   * given to [connectionUser] who may (for example) assign it to a [RealCall.connection].
   *
   * This confirms the returned connection is healthy before returning it. If this encounters any
   * unhealthy connections in its search, this will clean them up.
   *

    )
  }

  /**
   * Process the next protocol frame.
   *
   *  * If it is a control frame this will result in a single call to [FrameCallback].
   *  * If it is a message frame this will result in a single call to [FrameCallback.onReadMessage].
   *    If the message spans multiple frames, each interleaved control frame will result in a
   *    corresponding call to [FrameCallback].
   */
  @Throws(IOException::class)