/**
   * Inform peer that an additional `windowSizeIncrement` bytes can be sent on `streamId`, or the
   * connection if `streamId` is zero.
   */
  @Throws(IOException::class)
  fun windowUpdate(
    streamId: Int,
    windowSizeIncrement: Long,
  ) {
    withLock {
      if (closed) throw IOException("closed")
      require(windowSizeIncrement != 0L && windowSizeIncrement <= 0x7fffffffL) {

      streamId: Int,
      windowSizeIncrement: Long,
    ) {
      if (streamId == 0) {
        withLock {
          writeBytesMaximum += windowSizeIncrement
          notifyAll()
        }
      } else {
        val stream = getStream(streamId)
        if (stream != null) {
          stream.withLock {
            stream.addBytesToWriteWindow(windowSizeIncrement)
          }
        }
      }

        val windowUpdate = peer.takeFrame()
        assertThat(windowUpdate.type).isEqualTo(Http2.TYPE_WINDOW_UPDATE)
        windowUpdateStreamIds.add(windowUpdate.streamId)
        assertThat(windowUpdate.windowSizeIncrement).isEqualTo(windowUpdateThreshold.toLong())
      }
      // connection
      assertThat(windowUpdateStreamIds).contains(0)
      // stream
      assertThat(windowUpdateStreamIds).contains(3)
    }
  }