byte[] bytes = new byte[16];
    secureRandom.nextBytes(bytes);
    return ByteString.of(bytes);
  }

  private HttpUrl redirectUrl() {
    return mockWebServer.url("/oauth/");
  }

  /** When the browser hits the redirect URL, use the provided code to ask Slack for a session. */
  @Override public MockResponse dispatch(RecordedRequest request) {
    HttpUrl requestUrl = mockWebServer.url(request.getPath());

    requestCount++

    if (cacheStrategy.networkRequest != null) {
      // If this is a conditional request, we'll increment hitCount if/when it hits.
      networkCount++
    } else if (cacheStrategy.cacheResponse != null) {
      // This response uses the cache and not the network. That's a cache hit.
      hitCount++
    }
  }

  @Synchronized internal fun trackConditionalCacheHit() {
    hitCount++
  }

 * save a small amount of file I/O and data copying.
 */
class Relay private constructor(
  /**
   * Read/write persistence of the upstream source and its metadata. Its layout is as follows:
   *
   *  * 16 bytes: either `OkHttp cache v1\n` if the persisted file is complete. This is another
   *    sequence of bytes if the file is incomplete and should not be used.

## Version 4.8.0

_2020-07-11_

 *  New: Change `HeldCertificate.Builder` to use its own ASN.1 certificate encoder. This is part
    of our effort to remove the okhttp-tls module's dependency on Bouncy Castle. We think Bouncy
    Castle is great! But it's a large dependency (6.5 MiB) and its security provider feature
    impacts VM-wide behavior.

 * limitations under the License.
 */
package okhttp3.tls.internal.der

import okio.ByteString

/**
 * Like a [ByteString], but whose bits are not necessarily a strict multiple of 8.
 */
internal data class BitString(
  val byteString: ByteString,
  /** 0-7 unused bits in the last byte. */
  val unusedBitsCount: Int,
) {
  // Avoid Long.hashCode(long) which isn't available on Android 5.
  override fun hashCode(): Int {

    val symbol: Int

    /** Number of bits represented in the terminal node. */
    val terminalBitCount: Int

    /** Construct an internal node. */
    constructor() {
      this.children = arrayOfNulls(256)
      this.symbol = 0 // Not read.
      this.terminalBitCount = 0 // Not read.
    }

    /** Construct a terminal node. */
    constructor(symbol: Int, bits: Int) {
      this.children = null

          source.readData(data)
        }

        in 5..7 -> {
          data.writeByte('\n'.code) // 'data' on a line of its own.
        }

        in 8..9 -> {
          id = source.readUtf8LineStrict().takeIf { it.isNotEmpty() }
        }

        in 10..12 -> {
          id = null // 'id' on a line of its own.
        }

        in 13..14 -> {
          type = source.readUtf8LineStrict().takeIf { it.isNotEmpty() }

    e: IOException,
  )

  /**
   * Called when the HTTP response was successfully returned by the remote server. The callback may
   * proceed to read the response body with [Response.body]. The response is still live until its
   * response body is [closed][ResponseBody]. The recipient of the callback may consume the response
   * body on another thread.
   *

    if (b == address.size) return null // Too many groups.

    // Read a delimiter.
    if (i + 2 <= limit && input.startsWith("::", startIndex = i)) {
      // Compression "::" delimiter, which is anywhere in the input, including its prefix.
      if (compress != -1) return null // Multiple "::" delimiters.
      i += 2
      b += 2
      compress = b
      if (i == limit) break
    } else if (b != 0) {
      // Group separator ":" delimiter.

 *
 * This class supports [asynchronous canceling][cancel]. This is intended to have the smallest
 * blast radius possible. If an HTTP/2 stream is active, canceling will cancel that stream but not
 * the other streams sharing its connection. But if the TLS handshake is still in progress then
 * canceling may break the entire connection.
 */
class RealCall(
  val client: OkHttpClient,