this method is repeated below (DRY).
Let's take the `(glob: String, filter: PathFilter, conf: Configuration) => Boolean` out.

In fact, why not:
```scala
  def glob(glob: String, conf: Configuration, path: PathFilter = AcceptAll): Iterable[FileStatus]
``` 
then you can compose with the above?
```scala 
def isEmpty(glob: String, conf: Configuration, path: PathFilter = AcceptAll): Boolean =
  glob(glob, conf, path).isEmpty
```
etc…