code: def add_relationship_methods(self):
          
          Entry = apps.get_model('wagtailrelations', 'Entry')
  
          @cached_property
          def related(instance):
              return instance.get_related()
  
          @cached_property
          def related_live(instance):
              return instance.get_related_live()
  
          @cached_property
          def related_with_scores(instance):
              return instance.get_related_with_scores()
  
          def get_related(instance):
               entry = Entry.objects.get_for_model(instance)[0]
               return entry.get_related()
  
          def get_related_live(instance):
               entry = Entry.objects.get_for_model(instance)[0]
               return entry.get_related_live()
  
          def get_related_with_scores(instance):
              try:
                  entry = Entry.objects.get_for_model(instance)[0]
                  return entry.get_related_with_scores()
              except IntegrityError:
                  return []
  
          for model in self.applicable_models:
              model.add_to_class(
                  'get_related',
                  get_related
              )
              model.add_to_class(
                  'get_related_live',
                  get_related_live
              )
              model.add_to_class(
                  'get_related_with_scores',
                  get_related_with_scores
              )
              model.add_to_class(
                  'related',
                  related
              )
              model.add_to_class(
                  'related_live',
                  related_live
              )
              model.add_to_class(
                  'related_with_scores',
                  related_with_scores
              )
docs: Adds relationship methods to applicable model classes.