old_contents: from django.contrib import admin
  from image_cropping.admin import ImageCroppingMixin
  from models import Image, ImageFK
  
  
  class ImageFKAdmin(ImageCroppingMixin, admin.ModelAdmin):
      pass
  
  
  admin.site.register(Image)
  admin.site.register(ImageFK, ImageFKAdmin)
  
new_contents: from django.contrib import admin
  from image_cropping.admin import ImageCroppingMixin
  from models import Image, ImageFK
  
  
  class ImageFKAdmin(ImageCroppingMixin, admin.ModelAdmin):
      pass
  
  
  class ImageAdmin(ImageCroppingMixin, admin.ModelAdmin):
      pass
  
  admin.site.register(Image, ImageAdmin)
  admin.site.register(ImageFK, ImageFKAdmin)
  
subject: Use ImageCroppingMixin in tests