check(!closed) { "closed" }
      checkOffsetAndCount(source.size, 0, byteCount)
      sink.write(source, byteCount)
    }

    override fun flush() {
      if (closed) return // Don't throw; this stream might have been closed on the caller's behalf.
      sink.flush()
    }

    override fun close() {
      if (closed) return
      closed = true
      detachTimeout(timeout)