Datasets generated by this extractor.
Extract a single WikiPage.
Determine the extension of a WikiPage.
None if no extension exists, Some[String] if an extension was found.
when extractor needs some finalization
Generate quads that describe the file types for an extension.
Generate Quads for the StillImage pointed to by this file, including: <resource> foaf:depiction <file> <file> foaf:thumbnail <image-thumbnail>
when extractor has a pre-phase