* least one byte left to read.
     */
    private fun currentPartBytesRemaining(maxByteCount: Long): Long {
      val toIndex = minOf(source.buffer.size, maxByteCount) + 1L
      val boundaryIndex =
        source.indexOf(
          bytes = crlfDashDashBoundary,
          fromIndex = 0L,
          toIndex = toIndex,
        )

      byteCount: Long,
    ): Long {
      require(byteCount >= 0L) { "byteCount < 0: $byteCount" }
      check(!closed) { "closed" }
      if (bytesRemaining == 0L) return -1

      val read = super.read(sink, minOf(bytesRemaining, byteCount))
      if (read == -1L) {
        carrier.noNewExchanges() // The server didn't supply the promised content length.
        val e = ProtocolException("unexpected end of stream")

        val effectiveHeaderTableSize = minOf(headerTableSizeSetting, SETTINGS_HEADER_TABLE_SIZE_LIMIT)

        if (maxDynamicTableByteCount == effectiveHeaderTableSize) return // No change.

        if (effectiveHeaderTableSize < maxDynamicTableByteCount) {
          smallestHeaderTableSizeSetting =
            minOf(smallestHeaderTableSizeSetting, effectiveHeaderTableSize)
        }

      val ageMillis = cacheResponseAge()
      var freshMillis = computeFreshnessLifetime()

      if (requestCaching.maxAgeSeconds != -1) {
        freshMillis = minOf(freshMillis, SECONDS.toMillis(requestCaching.maxAgeSeconds.toLong()))
      }

      var minFreshMillis: Long = 0
      if (requestCaching.minFreshSeconds != -1) {

  val originalDurationNs =
    if (timeout().hasDeadline()) {
      timeout().deadlineNanoTime() - nowNs
    } else {
      Long.MAX_VALUE
    }
  timeout().deadlineNanoTime(nowNs + minOf(originalDurationNs, timeUnit.toNanos(duration.toLong())))
  return try {
    val skipBuffer = Buffer()
    while (read(skipBuffer, 8192) != -1L) {
      skipBuffer.clear()
    }

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

        toWrite = minOf(byteCount, writeBytesMaximum - writeBytesTotal).toInt()
        toWrite = minOf(toWrite, writer.maxDataLength())
        writeBytesTotal += toWrite.toLong()
      }

      byteCount -= toWrite.toLong()

        padding = 0
        if (flags and FLAG_END_HEADERS != 0) return -1L
        readContinuationHeader()
        // TODO: test case for empty continuation header?
      }

      val read = source.read(sink, minOf(byteCount, left.toLong()))
      if (read == -1L) return -1L
      left -= read.toInt()
      return read
    }

    override fun timeout(): Timeout = source.timeout()

    @Throws(IOException::class)

    val buffer = Buffer()
    var receivedByteCount = 0L

    @Throws(IOException::class)
    override fun write(
      source: Buffer,
      byteCount: Long,
    ) {
      val toRead = minOf(remainingByteCount, byteCount)
      if (toRead > 0L) {
        source.read(buffer, toRead)
      }
      val toSkip = byteCount - toRead
      if (toSkip > 0L) {
        source.skip(toSkip)
      }