code: def subset(self, subset_id):
          
          if subset_id in self.subsetcache:
              return self.subsetcache[subset_id]
          set_uri = self.get_set_uri(subset_id)
          for row in self.graph.query("SELECT ?seturi ?setid ?setlabel ?setopen WHERE { ?seturi rdf:type skos:Collection . OPTIONAL { ?seturi skos:notation ?setid } OPTIONAL { ?seturi skos:prefLabel ?setlabel } OPTIONAL { ?seturi fsd:open ?setopen } FILTER (?seturi = <" + str(set_uri)+">) }"):
              self.subsetcache[str(row.setid)] = {'uri': str(row.seturi), 'id': str(row.setid), 'label': str(row.setlabel) if row.setlabel else "", 'open': bool(row.setopen) }
              return self.subsetcache[str(row.setid)]
          raise DeepValidationError("Unable to find subset (set_uri=" + str(set_uri)+")")
docs: Returns information regarding the set