Extracts the first image of a Wikipedia page. Constructs a thumbnail from it, and
the full size image.
FIXME: we're sometimes dealing with encoded links, sometimes with decoded links. It's quite a mess.
(Since version 2017-08) replaced by ImageExtractorNew
Datasets generated by this extractor.
Datasets generated by this extractor. Used for serialization. If a mapping implementation
does not return all datasets it produces, serialization may fail.
The subject URI of the generated triples
A graph holding the extracted data
when extractor needs some finalization
when extractor has a pre-phase