How to programatically create a library and add it to a module?

I'm about to programmatically create a library (from scala test jar) and want to add it as dependency to my module. the code I'm using to create my library looks like

So far, I managed to get to the point to see my library listed under the "External Libraries" entry of the project, yet I does no appear in the Library entry of the module settings and adding it programmatically via

or

always yields a NullPointerException as the LibraryTable of my library is empty (so far, I guess this is the problem, as debugging resolved).
Can anybody give me a hint of what I'm forgetting to do (I hope it's not that much that is missing).

Thanks a lot in advance!

Cheers,

Phil

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Original message URL: http://devnet.jetbrains.net/message/5475802#5475802