old_contents: from comics.aggregator.crawler import CrawlerBase, CrawlerImage
  from comics.meta.base import MetaBase
  
  class Meta(MetaBase):
      name = 'Treading Ground'
      language = 'en'
      url = 'http://www.treadingground.com/'
      start_date = '2003-10-12'
      rights = 'Nick Wright'
  
  class Crawler(CrawlerBase):
      history_capable_days = 30
      schedule = 'Mo,We,Fr'
      time_zone = -5
  
      def crawl(self, pub_date):
          pass
  
new_contents: from comics.aggregator.crawler import CrawlerBase, CrawlerImage
  from comics.meta.base import MetaBase
  
  class Meta(MetaBase):
      name = 'Treading Ground'
      language = 'en'
      url = 'http://www.treadingground.com/'
      start_date = '2003-10-12'
      rights = 'Nick Wright'
  
  class Crawler(CrawlerBase):
      schedule = None
  
      def crawl(self, pub_date):
          pass # Comic no longer published
  
subject: Remove schedule for ended comic