code: def add_ago_to_since(since: str) -> str:
      
      since_words = since.split(' ')
      grains = ['days', 'years', 'hours', 'day', 'year', 'weeks']
      if (len(since_words) == 2 and since_words[1] in grains):
          since += ' ago'
      return since
docs: Backwards compatibility hack. Without this slices with since: 7 days will
      be treated as 7 days in the future.
  
      :param str since:
      :returns: Since with ago added if necessary
      :rtype: str