val prefix = header.readByteString(PREFIX_CLEAN.size.toLong())
      if (prefix != PREFIX_CLEAN) throw IOException("unreadable cache file")
      val upstreamSize = header.readLong()
      val metadataSize = header.readLong()

      // Read the metadata.
      val metadataBuffer = Buffer()
      fileOperator.read(FILE_HEADER_SIZE + upstreamSize, metadataBuffer, metadataSize)

    metadata: ByteString?,
  ) {
    val source = file.source().buffer()
    assertThat(source.readByteString(prefix.size.toLong())).isEqualTo(prefix)
    assertThat(source.readLong()).isEqualTo(upstreamSize)
    assertThat(source.readLong()).isEqualTo(metadataSize.toLong())
    if (upstream != null) {
      assertThat(source.readUtf8(upstreamSize)).isEqualTo(upstream)
    }
    if (metadata != null) {

      name = "INTEGER",
      tagClass = DerHeader.TAG_CLASS_UNIVERSAL,
      tag = 2L,
      codec =
        object : BasicDerAdapter.Codec<Long> {
          override fun decode(reader: DerReader): Long = reader.readLong()

          override fun encode(
            writer: DerWriter,
            value: Long,
          ) = writer.writeLong(value)
        },
    )

  val INTEGER_AS_BIG_INTEGER =
    BasicDerAdapter(

      )
    }

    // Get frame length, optionally reading from follow-up bytes if indicated by special values.
    frameLength = (b1 and B1_MASK_LENGTH).toLong()
    if (frameLength == PAYLOAD_SHORT.toLong()) {
      frameLength = (source.readShort() and 0xffff).toLong() // Value is unsigned.
    } else if (frameLength == PAYLOAD_LONG.toLong()) {
      frameLength = source.readLong()
      if (frameLength < 0L) {

    if (bytesLeft == 0L) throw ProtocolException("unexpected length: $bytesLeft at $this")
    val byteArray = source.readByteArray(bytesLeft)
    return BigInteger(byteArray)
  }

  fun readLong(): Long {
    if (bytesLeft !in 1..8) throw ProtocolException("unexpected length: $bytesLeft at $this")

    var result = source.readByte().toLong() // No "and 0xff" because this is a signed value!

    "--connect-timeout",
    help = "Maximum time allowed for connection (seconds)",
  ).int().default(DEFAULT_TIMEOUT)

  val readTimeout: Int by option("--read-timeout", help = "Maximum time allowed for reading data (seconds)").int().default(DEFAULT_TIMEOUT)

  val callTimeout: Int by option(
    "--call-timeout",
    help = "Maximum time allowed for the entire call (seconds)",
  ).int().default(DEFAULT_TIMEOUT)

    val response = call.execute()
    val inputStream = response.body.byteStream()
    assertThat(inputStream.read().toChar()).isEqualTo('A')
    call.cancel()
    assertFailsWith<IOException> {
      // Reading 'B' may succeed if it's buffered.
      inputStream.read()

      // But 'C' shouldn't be buffered (the response is throttled) and this should fail.
      inputStream.read()
    }
    inputStream.close()

   */
  object DisconnectAtEnd : SocketPolicy

  /**
   * Request immediate close of connection without even reading the request. Use to simulate buggy
   * SSL servers closing connections in response to unrecognized TLS extensions.
   */
  object DisconnectAtStart : SocketPolicy

  /**
   * Close connection after reading the request but before writing the response. Use this to
   * simulate late connection pool failures.
   */

    check(state == STATE_OPEN_RESPONSE_BODY) { "state: $state" }
    state = STATE_READING_RESPONSE_BODY
    return FixedLengthSource(length)
  }

  private fun newChunkedSource(url: HttpUrl): Source {
    check(state == STATE_OPEN_RESPONSE_BODY) { "state: $state" }
    state = STATE_READING_RESPONSE_BODY
    return ChunkedSource(url)
  }

  private fun newUnknownLengthSource(): Source {

Consider an application streaming a video over http/2. Perhaps the user pauses the video and the application stops reading bytes from this stream. The buffer will fill up, and flow control prevents the server from sending more data on this stream. When the user unpauses her video the buffer drains, the read is acknowledged, and the server proceeds to stream data.