code: def linkify(self, timeperiods, commands):
          
          self.linkify_with_timeperiods(timeperiods, 'service_notification_period')
          self.linkify_with_timeperiods(timeperiods, 'host_notification_period')
          self.linkify_command_list_with_commands(commands, 'service_notification_commands')
          self.linkify_command_list_with_commands(commands, 'host_notification_commands')
docs: Create link between objects::
  
           * notificationways -> timeperiods
           * notificationways -> commands
  
          :param timeperiods: timeperiods to link
          :type timeperiods: alignak.objects.timeperiod.Timeperiods
          :param commands: commands to link
          :type commands: alignak.objects.command.Commands
          :return: None