old_contents: from django.db import models
  
  class Post(models.Model):
      body = models.TextField()
      title = models.CharField(max_length=50)
      display_title = models.CharField(max_length=50)
      publication_date = models.DateTimeField(auto_now_add=True)
  
      def __unicode__(self):
          return self.title
  
  class Comment(models.Model):
      text = models.TextField()
      author = models.CharField(max_length=100)
      date = models.DateTimeField(auto_now_add=True)
      post = models.ForeignKey(Post)
  
      def __unicode__(self):
          return self.author + u"'s comment on " + self.post.__unicode__()
  
  
new_contents: from django.db import models
  
  class Post(models.Model):
      body = models.TextField()
      title = models.CharField(max_length=50)
      publication_date = models.DateTimeField(auto_now_add=True)
  
      def __unicode__(self):
          return self.title
  
  class Comment(models.Model):
      text = models.TextField()
      author = models.CharField(max_length=100)
      date = models.DateTimeField(auto_now_add=True)
      post = models.ForeignKey(Post)
  
      def __unicode__(self):
          return self.author + u"'s comment on " + self.post.__unicode__()
  
  
subject: Remove display_title field from Post model.