Swift NSDirectoryEnumerator Generator

Question

When I use

let fileEnumerator = self.fileManager.enumeratorAtURL(diskCacheURL,
    includingPropertiesForKeys: resourceKeys,
    options: NSDirectoryEnumerationOptions.SkipsHiddenFiles, 
    errorHandler: nil)

for fileURL in fileEnumerator {

}

I get error:

'NSDirectoryEnumerator' does not have a member named 'Generator'

How can I enumerate through all elements in NSDirectoryEnumerator.