This munge option will transform all blank nodes as IRIs following RDF 1.1 specs section 3.5.
_:a8d14fa93486370345412093add8f50c will become http://www.wikidata.org/.well-known/genid/a8d14fa93486370345412093add8f50c
Wikibase is expected to generate stable and unique labels for its blank node labels (https://gerrit.wikimedia.org/r/c/mediawiki/extensions/Wikibase/+/583897).