docs: def visitQualifier(self, ctx: ShExDocParser.QualifierContext):
          """ qualifier: includeSet | extraPropertySet | KW_CLOSED """
          if ctx.includeSet():
              if self.shape.inherit is None:
                  self.shape.inherit = []
              self.shape.inherit += [self.context.tripleexprlabel_to_iriref(tel)
                                     for tel in ctx.includeSet().tripleExpressionLabel()]
          elif ctx.extraPropertySet():
              if self.shape.extra is None:
                  self.shape.extra = []
              self.shape.extra += [self.context.predicate_to_IRI(p) for p in ctx.extraPropertySet().predicate()]
  
          elif ctx.KW_CLOSED():
              self.shape.closed = True