I tend to write code like this because I mess up the class paths every time:

```
val personSource = {
    val resourcePath = "/edu/knowitall/tac2013/findSlotFillersApp/PersonSlotTypes.txt"
    val url = getClass.getResource("/my/resource/here")
    require(url != null, "Could not find resource: " + resourcePath)
    Source.fromURL(url)
}
```

It's verbose but it tells you exactly what happened, instead of NPE.