old_contents: from django.db import models
  
  
  class OrderableManager(models.Manager):
      '''
      Adds additional functionality to `Orderable.objects` allow access to the next and
      previous ordered object within the queryset.
      '''
      def before(self, orderable):
          return self.filter(sort_order__lt=orderable.sort_order).last()
  
      def after(self, orderable):
          return self.filter(sort_order__gt=orderable.sort_order).first()
  
new_contents: from django.db import models
  
  
  class OrderableManager(models.Manager):
      '''
      Adds additional functionality to `Orderable.objects` providing access to the next and
      previous ordered object within the queryset.
      '''
      def before(self, orderable):
          return self.filter(sort_order__lt=orderable.sort_order).last()
  
      def after(self, orderable):
          return self.filter(sort_order__gt=orderable.sort_order).first()
  
subject: fix typo