old_contents: # -*- coding: utf-8 -*-
  import django.dispatch
  
  
  add_log = django.dispatch.Signal(providing_args=['data'])
  send_mail = django.dispatch.Signal(providing_args=['data'])
  
new_contents: # -*- coding: utf-8 -*-
  import django.dispatch
  
  
  add_log = django.dispatch.Signal(providing_args=['data', 'meta'])
  
subject: Remove unnecessary signal