new_contents: class TweetSorter:
      """
        Sort out tweets which include image.
      """
      def __init__(self):
          pass
  
      def __call__(self, tweets):
          tweets = [item for item in tweets if self.sort(item)]
          return tweets
  
      def sort(self, tweet):
          if "extended_entities" in tweet:
              for media in tweet["extended_entities"]["media"]:
                  if "jpg" in media["media_url"]:
                      return tweet
              else:
                  return 0
          else:
              return 0
  
subject: Add sorter