}

  @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")
    }

interface PushObserver {
  /**
   * Describes the request that the server intends to push a response for.
   *
   * @param streamId server-initiated stream ID: an even number.
   * @param requestHeaders minimally includes `:method`, `:scheme`, `:authority`,
   * and `:path`.
   */
  fun onRequest(
    streamId: Int,
    requestHeaders: List<Header>,
  ): Boolean

  /**

        logger.fine(
          frameLogWindowUpdate(
            inbound = false,
            streamId = streamId,
            length = 4,
            windowSizeIncrement = windowSizeIncrement,
          ),
        )
      }
      frameHeader(
        streamId = streamId,
        length = 4,
        type = TYPE_WINDOW_UPDATE,
        flags = FLAG_NONE,
      )

    streamId: Int,
    requestHeaders: List<Header>,
  ) {
    this.withLock {
      if (streamId in currentPushRequests) {
        writeSynResetLater(streamId, ErrorCode.PROTOCOL_ERROR)
        return
      }
      currentPushRequests.add(streamId)
    }
    pushQueue.execute("$connectionName[$streamId] onRequest") {
      val cancel = pushObserver.onRequest(streamId, requestHeaders)
      ignoreIoExceptions {

      TYPE_DATA -> readData(handler, length, flags, streamId)
      TYPE_HEADERS -> readHeaders(handler, length, flags, streamId)
      TYPE_PRIORITY -> readPriority(handler, length, flags, streamId)
      TYPE_RST_STREAM -> readRstStream(handler, length, flags, streamId)
      TYPE_SETTINGS -> readSettings(handler, length, flags, streamId)
      TYPE_PUSH_PROMISE -> readPushPromise(handler, length, flags, streamId)

      inFinished: Boolean,
      streamId: Int,
      source: BufferedSource,
      length: Int,
    ) {
      check(type == -1)
      this.type = Http2.TYPE_DATA
      this.inFinished = inFinished
      this.streamId = streamId
      this.data = source.readByteString(length.toLong()).toByteArray()
    }

    override fun rstStream(
      streamId: Int,
      errorCode: ErrorCode,
    ) {

   *
   * ```
   * direction streamID length type flags
   * ```
   *
   * Where direction is `<<` for inbound and `>>` for outbound.
   *
   * For example, the following would indicate a HEAD request sent from the client.
   * ```
   * `<< 0x0000000f    12 HEADERS       END_HEADERS|END_STREAM
   * ```
   */
  fun frameLog(
    inbound: Boolean,
    streamId: Int,
    length: Int,
    type: Int,

  override fun data(
    inFinished: Boolean,
    streamId: Int,
    source: BufferedSource,
    length: Int,
  ) {
    fail("")
  }

  override fun headers(
    inFinished: Boolean,
    streamId: Int,
    associatedStreamId: Int,
    headerBlock: List<Header>,
  ) {
    fail("")
  }

  override fun rstStream(
    streamId: Int,
    errorCode: ErrorCode,
  ) {
    fail("")
  }

    check(acknowledged >= 0)

    this.total += total
    this.acknowledged += acknowledged

    check(this.acknowledged <= this.total)
  }

  override fun toString(): String {
    return "WindowCounter(streamId=$streamId, total=$total, acknowledged=$acknowledged, unacknowledged=$unacknowledged)"
  }

  /**
   * Notification that the receiving stream flow control window has changed.
   * [WindowCounter] generally carries the client view of total and acked bytes.
   */
  fun receivingStreamWindowChanged(
    streamId: Int,
    windowCounter: WindowCounter,
    bufferSize: Long,
  )

  /**
   * Notification that the receiving connection flow control window has changed.