old_contents: import re
  import json
  from uuid import uuid4
  
  import requests
  
  from django.db import models
  from django.core.urlresolvers import reverse
  from django.contrib.sites.models import get_current_site
  from django.core.files.base import ContentFile
  from django.contrib.auth.models import User
  
  from wafer.utils import normalize_unicode
  from wafer import constants
  
  
  class Talks(models.Model):
  
      talk_id = models.IntegerField(primary_key=True)
  
      title = models.CharField(max_length=1024)
  
      abstract = models.TextField()
  
      finalised = models.BooleanField(default=False)
      accepted = models.BooleanField(default=False)
  
      corresponding_author = models.ForeignKey(User,
              related_name='contact_talks')
      authors = models.ManyToManyField(User)
  
new_contents: from django.db import models
  from django.contrib.auth.models import User
  
  
  class Talks(models.Model):
  
      talk_id = models.IntegerField(primary_key=True)
  
      title = models.CharField(max_length=1024)
  
      abstract = models.TextField()
  
      finalised = models.BooleanField(default=False)
      accepted = models.BooleanField(default=False)
  
      corresponding_author = models.ForeignKey(User,
              related_name='contact_talks')
      authors = models.ManyToManyField(User)
  
subject: Remove unused imports