code: def applicable_models(self):
          
          Page        = apps.get_model('wagtailcore', 'Page')
          applicable  = []
  
          for model in apps.get_models():
              if issubclass(model, Page):
                  applicable.append(model)
  
          return applicable
docs: Returns a list of model classes that subclass Page.
  
          :rtype: list.