text: from django import dispatch
  
  before_add = dispatch.Signal(
      providing_args=['comment', 'data', 'preview', 'user'])
  
  # returning result on "after add" that is bool(result) == True will make
  # comment save again. So you do not need to re-save comment changes in signal
  # receivers
  after_add = dispatch.Signal(
      providing_args=['comment', 'data', 'preview', 'user'])
  
  on_delete = dispatch.Signal(providing_args=['comment', 'user'])
  on_thread_delete = dispatch.Signal(providing_args=['instance', 'mutation'])
  on_update = dispatch.Signal(
      providing_args=['comment', 'data', 'preview', 'user'])
  
  to_json = dispatch.Signal(providing_args=['comment', 'data', 'user'])
  