code: def cron(cronline, venusian_category='irc3.plugins.cron'):
      
      def wrapper(func):
          def callback(context, name, ob):
              obj = context.context
              crons = obj.get_plugin(Crons)
              if info.scope == 'class':
                  callback = getattr(
                      obj.get_plugin(ob),
                      func.__name__)
              else:
                  callback = irc3.utils.wraps_with_context(func, obj)
              crons.add_cron(cronline, callback)
          info = venusian.attach(func, callback, category=venusian_category)
          return func
      return wrapper
docs: main decorator