code: def marvcli_undiscard(datasets):
      
      create_app()
  
      setids = parse_setids(datasets, discarded=True)
      dataset = Dataset.__table__
      stmt = dataset.update()\
                    .where(dataset.c.setid.in_(setids))\
                    .values(discarded=False)
      db.session.execute(stmt)
      db.session.commit()
docs: Undiscard DATASETS previously discarded.