new_contents: from django.core.management.base import BaseCommand
  
  from timeside.server.models import Item
  
  
  class Command(BaseCommand):
      help = "This command will generate all post_save callback and will thus create audio_duration, mime_type and sha1 field if missing"
  
      def handle(self, *args, **options):
          for item in Item.objects.all():
              item.save()
  
subject: Add management command to update Item fields that gets updated after save()