Already has: (You should also throw an error if the number passed to the function is not valid, and not a single-digit number.) Maybe you missed it?

The Java implementation is the only one that uses streams. I'd require it of the Python implementation too, but it's kind of late for that. Javascript and CoffeeScript, meanwhile, don't have streams.

1. Can you clarify?
2. Could you suggest how I might improve the kata description to clarify what problems you ran into here? Also, could you clarify what you expected vs what was the actual behavior? If I'm remembering correctly, the only requirements for the output stream should be flushing before input streams and at the end of execution.
3. I believe this is expected behavior, but just to be sure, want to give feedback on which tests triggered this?
4. This is a problem, so thanks for pointing it out. The person who kumited used BufferedReader's read and readline methods. Do you think adding to the description that input should be handled using or emulating BufferedReader's read and readLine methods makes sense? If not, would you be willing to provide an alternative description?

Just tried them, no problem at all.