* write window. This method will block until the write window is nonempty.
     */
    @Throws(IOException::class)
    private fun emitFrame(outFinishedOnLastFrame: Boolean) {
      val toWrite: Long
      val outFinished: Boolean
      withLock {
        writeTimeout.enter()
        try {
          while (writeBytesTotal >= writeBytesMaximum &&