old_contents: from django.db import models
  
  from pyuploadcare.dj.models import FileField, ImageField, ImageGroupField
  
  
  class Gallery(models.Model):
  
      title = models.CharField(max_length=255)
  
      def __unicode__(self):
          return self.title
  
  
  class Photo(models.Model):
  
      gallery = models.ForeignKey(Gallery)
      title = models.CharField(max_length=255)
      arbitrary_file = FileField(blank=True, null=True)
      photo_2x3 = ImageField(manual_crop='2:3', blank=True)
  
      def __unicode__(self):
          return self.title
  
  
  class GalleryMultiupload(models.Model):
  
      title = models.CharField(max_length=255)
      photos = ImageGroupField()
  
      def __unicode__(self):
          return self.title
  
new_contents: from django.db import models
  
  from pyuploadcare.dj.models import FileField, ImageField, ImageGroupField
  
  
  class Gallery(models.Model):
  
      title = models.CharField(max_length=255)
  
      def __unicode__(self):
          return self.title
  
  
  class Photo(models.Model):
  
      gallery = models.ForeignKey(Gallery, on_delete=models.CASCADE)
      title = models.CharField(max_length=255)
      arbitrary_file = FileField(blank=True, null=True)
      photo_2x3 = ImageField(manual_crop='2:3', blank=True)
  
      def __unicode__(self):
          return self.title
  
  
  class GalleryMultiupload(models.Model):
  
      title = models.CharField(max_length=255)
      photos = ImageGroupField()
  
      def __unicode__(self):
          return self.title
  
subject: Add `on_delete` argument for `Photo.gallery` field