accumulator = (accumulator shl codeBitCount) or code.toLong()
      accumulatorBitCount += codeBitCount

      while (accumulatorBitCount >= 8) {
        accumulatorBitCount -= 8
        sink.writeByte((accumulator shr accumulatorBitCount).toInt())
      }
    }

    if (accumulatorBitCount > 0) {
      accumulator = accumulator shl (8 - accumulatorBitCount)

        while (true) {
          val b = readByte()
          if (b and 0x80 != 0) { // Equivalent to (b >= 128) since b is in [0..255].
            result += b and 0x7f shl shift
            shift += 7
          } else {
            result += b shl shift // Last byte.
            break
          }
        }
        return result
      }

      /** Reads a potentially Huffman encoded byte string. */

            throw ProtocolException("invalid encoding for length")
          }

          for (i in 1 until lengthBytes) {
            lengthBits = lengthBits shl 8
            lengthBits += source.readByte().toInt() and 0xff
          }

          if (lengthBits < 0) throw ProtocolException("length > Long.MAX_VALUE")

          lengthBits
        }
        else -> {

  writeByte(medium.ushr(8) and 0xff)
  writeByte(medium and 0xff)
}

@Throws(IOException::class)
internal fun BufferedSource.readMedium(): Int =
  (
    readByte() and 0xff shl 16
      or (readByte() and 0xff shl 8)
      or (readByte() and 0xff)
  )

/** Run [block] until it either throws an [IOException] or completes. */
internal inline fun ignoreIoExceptions(block: () -> Unit) {
  try {
    block()

    // Read a group, one to four hex digits.
    var value = 0
    groupOffset = i
    while (i < limit) {
      val hexDigit = input[i].parseHexDigit()
      if (hexDigit == -1) break
      value = (value shl 4) + hexDigit
      i++
    }
    val groupLength = i - groupOffset
    if (groupLength == 0 || groupLength > 4) return null // Group is the wrong size.

  }

  @Test fun streamIdHasReservedBit() {
    val writer = Http2Writer(Buffer(), true)
    assertFailsWith<IllegalArgumentException> {
      var streamId = 3
      streamId = streamId or (1L shl 31).toInt() // set reserved bit
      writer.frameHeader(streamId, Http2.INITIAL_MAX_FRAME_SIZE, Http2.TYPE_DATA, FLAG_NONE)
    }.also { expected ->
      assertThat(expected.message).isEqualTo("reserved bit set: -2147483645")