code: def mark_read(request, message_id, dispatch_id, hashed, redirect_to=None):
      
      if redirect_to is None:
          redirect_to = get_static_url('img/sitemessage/blank.png')
  
      return _generic_view(
          'handle_mark_read_request', sig_mark_read_failed,
          request, message_id, dispatch_id, hashed, redirect_to=redirect_to
      )
docs: Handles mark message as read request.
  
      :param Request request:
      :param int message_id:
      :param int dispatch_id:
      :param str hashed:
      :param str redirect_to:
      :return: