old_contents: import datetime
  from django.db import models
  from django.contrib.contenttypes import generic
  from django.contrib.contenttypes.models import ContentType
  
  from .managers import WellManager
  
  
  class Well(models.Model):
      title = models.SlugField()
      pub_date = models.DateTimeField()
      expires = models.DateTimeField(null=True)
      active = models.BooleanField(default=True)
  
      objects = WellManager()
  
      def __unicode__(self):
          return "%s (%s)" % (self.title, self.pub_date)
  
      def save(self, *args, **kwargs):
          if not self.pub_date:
              self.pub_date = datetime.datetime.now()
          return super(Well, self).save(*args, **kwargs)
  
  
  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: import datetime
  from django.db import models
  from django.contrib.contenttypes import generic
  from django.contrib.contenttypes.models import ContentType
  
  from .managers import WellManager
  
  
  class Well(models.Model):
      title = models.CharField(max_length=100)
      pub_date = models.DateTimeField()
      expires = models.DateTimeField(null=True)
      active = models.BooleanField(default=True)
  
      objects = WellManager()
  
      def __unicode__(self):
          return "%s (%s)" % (self.title, self.pub_date)
  
      def save(self, *args, **kwargs):
          if not self.pub_date:
              self.pub_date = datetime.datetime.now()
          return super(Well, self).save(*args, **kwargs)
  
  
  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: change to be a basic text string