Merge chunks to single files?

[tunnckoCore]

Hello,
Directly to question: How to merge all created chunks in temporary folder to single files? :) I can't see method for this?
Otherwise, lib is useless - i guess?

[AidasK]

PHP:
https://github.com/flowjs/flow-php-server
https://github.com/flowjs/flow.js/blob/master/samples/Backend%20on%20PHP.md

Java:
https://github.com/flowjs/flow.js/tree/master/samples/java