code: def add_text_structure(self, label):
          
  
          ts = self.session.get_resource("%s/text_structure" % self.subject
                                        , self.session.get_class(surf.ns.HUCIT['TextStructure']))
          ts.rdfs_label.append(Literal(label))
          ts.save()
          self.hucit_has_structure = ts
          self.update()
          return self.hucit_has_structure.one
docs: Adds a citable text structure to the work.