Because of [this](https://github.com/scala-ide/scala-ide-play2/pull/171/files#L0R40), I'm now having the impression that the side-effect is only needed to be visible inside the method, not outside of it. If that's the case, maybe you could change the signature of the method and declare ``fs`` of type ``List``. Then, inside the method, declare a local variable of type ``ListBuffer`` and append all elements in ``fs`` to it.