)
      sink.writeInt(promisedStreamId and 0x7fffffff)
      sink.write(hpackBuffer, length.toLong())

      if (byteCount > length) writeContinuationFrames(streamId, byteCount - length)
    }
  }

  @Throws(IOException::class)
  fun flush() {
    this.withLock {
      if (closed) throw IOException("closed")
      sink.flush()
    }
  }