title: Why can't Scala find org.apache.commons.lang package?
body: <p>I want to use <a href="http://commons.apache.org/lang/api-2.4/org/apache/commons/lang/NotImplementedException.html">org.apache.commons.lang.NotImplementedException</a> as it seems to be the only NotImplementedException implementation in Java/Scala domain. I can remember I used to use it with Scala 2.8.1 with no hacks. But now it says "object lang is not a member of package org.apache.commons". Where has org.apache.commons.lang gone?</p>