code: def key_validation_check(tweet_keys_list, superset_keys, minset_keys):
      
      # check for keys that must be present
      tweet_keys = set(tweet_keys_list)
      minset_overlap = tweet_keys & minset_keys
      if minset_overlap != minset_keys:
          raise UnexpectedFormatError("keys ({}) missing from Tweet (Public API data is not supported)"
                                      .format(minset_keys - tweet_keys))
      # check for keys that could be present
      unexpected_keys = tweet_keys - superset_keys
      if len(unexpected_keys) > 0:
          raise UnexpectedFormatError("Unexpected keys ({}) are in this Tweet"
                                      .format(unexpected_keys))
      return 0
docs: Validates the keys present in a Tweet.
  
      Args:
          tweet_keys_list (list): the keys present in a tweet
          superset_keys (set): the set of all possible keys for a tweet
          minset_keys (set): the set of minimal keys expected in a tweet.
  
      Returns:
          0 if no errors
  
      Raises:
          UnexpectedFormatError on any mismatch of keys.