old_contents: from django.db import models
  from django.contrib.contenttypes import generic
  from django.contrib.contenttypes.models import ContentType
  
  
  class Well(models.Model):
      title = models.SlugField()
  
      def add(self, *args, **kwargs):
          pass
  
  
  class Node(models.Model):
      well = models.ForeignKey(Well, related_name="nodes")
      order = models.IntegerField(default=0)
      content_type = models.ForeignKey(ContentType)
      object_id = models.PositiveIntegerField()
      content_object = generic.GenericForeignKey('content_type', 'object_id')
  
      class Meta:
          ordering = ["order"]
  
      def __unicode__(self):
          return "%s (%d): %s" % (self.well.title, self.order,
                                  self.content_object)
  
new_contents: from django.db import models
  from django.contrib.contenttypes import generic
  from django.contrib.contenttypes.models import ContentType
  
  
  class Well(models.Model):
      title = models.SlugField()
  
  
  class Node(models.Model):
      well = models.ForeignKey(Well, related_name="nodes")
      order = models.IntegerField(default=0)
      content_type = models.ForeignKey(ContentType)
      object_id = models.PositiveIntegerField()
      content_object = generic.GenericForeignKey('content_type', 'object_id')
  
      class Meta:
          ordering = ["order"]
  
      def __unicode__(self):
          return "%s (%d): %s" % (self.well.title, self.order,
                                  self.content_object)
  
subject: remove boilerplate code that wasn't used