old_contents: from django.contrib.contenttypes import generic
  from django.contrib.contenttypes.models import ContentType
  from django.db import models
  
  # TODO: Refactor this into a generic utils app to remove the wells dep
  from armstrong.core.arm_wells.querysets import GenericForeignKeyQuerySet
  
  
  class Series(models.Model):
      title = models.CharField(max_length=250)
      description = models.TextField()
      slug = models.SlugField()
  
      def __unicode__(self):
          return self.title
  
      def get_items(self):
          return GenericForeignKeyQuerySet(self.nodes.all().select_related())
  
      @property
      def items(self):
          if not getattr(self, '_items', False):
              self._items = self.get_items()
          return self._items
  
  
  class SeriesNode(models.Model):
      series = models.ForeignKey(Series, 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')
  
new_contents: from django.contrib.contenttypes import generic
  from django.contrib.contenttypes.models import ContentType
  from django.db import models
  
  # TODO: Refactor this into a generic utils app to remove the wells dep
  from armstrong.core.arm_wells.querysets import GenericForeignKeyQuerySet
  
  
  class Series(models.Model):
      title = models.CharField(max_length=250)
      description = models.TextField()
      slug = models.SlugField()
  
      def __unicode__(self):
          return self.title
  
      def get_items(self):
          return GenericForeignKeyQuerySet(self.nodes.all().select_related())
  
      @property
      def items(self):
          if not getattr(self, '_items', False):
              self._items = self.get_items()
          return self._items
  
  
  class SeriesNode(models.Model):
      class Meta:
          ordering = ['order', ]
  
      series = models.ForeignKey(Series, 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')
  
subject: Add in missing default order