input: 
  def summarize_twitter_data(twitter_data: List[Dict[str, Union[str, int]]]) -> None:
      """ Visually summarize the Twitter data by plotting the tweet authors, number of likes, and number of retweets.
      Each tweet is represented as a dictionary with keys 'author', 'date', 'text', 'likes', and 'retweets'.
      >>> summarize_twitter_data([
      ...     {'author': 'User1', 'date': '2023-01-01', 'text': 'Hello world', 'likes': 10, 'retweets': 2},
      ...     {'author': 'User2', 'date': '2023-01-02', 'text': 'Python is great', 'likes': 15, 'retweets': 5},
      ...     {'author': 'User1', 'date': '2023-01-03', 'text': 'Another tweet', 'likes': 7, 'retweets': 1}
      ... ])
      """
      import matplotlib.pyplot as plt
      
      authors = [tweet['author'] for tweet in twitter_data]
      num_tweets = [authors.count(author) for author in set(authors)]
      plt.xlabel('Tweet Authors')
      plt.ylabel('Number of tweets')
      plt.title('Tweet Author Summary')
      plt.bar(set(authors), num_tweets)
      plt.show()
      
      tweets = [tweet['text'] for tweet in twitter_data]
      num_likes = [tweet['likes'] for tweet in twitter_data]
      plt.xlabel('Tweets')
      plt.ylabel('Number of Likes')
      plt.title('Number of Likes Summary')
      plt.bar(tweets, num_likes)
      plt.show()
      
      num_retweets = [tweet['retweets'] for tweet in twitter_data]
      plt.xlabel('Tweets')
      plt.ylabel('Number of Retweets')
      plt.title('Number of Retweets Summary')
      plt.bar(tweets, num_retweets)
      plt.show()
  
output:     import matplotlib.pyplot as plt
      
      authors = [tweet['author'] for tweet in twitter_data]
      num_tweets = [authors.count(author) for author in set(authors)]
      plt.xlabel('Tweet Authors')
      plt.ylabel('Number of tweets')
      plt.title('Tweet Author Summary')
      plt.bar(set(authors), num_tweets)
      plt.show()
      
      tweets = [tweet['text'] for tweet in twitter_data]
      num_likes = [tweet['likes'] for tweet in twitter_data]
      plt.xlabel('Tweets')
      plt.ylabel('Number of Likes')
      plt.title('Number of Likes Summary')
      plt.bar(tweets, num_likes)
      plt.show()
      
      num_retweets = [tweet['retweets'] for tweet in twitter_data]
      plt.xlabel('Tweets')
      plt.ylabel('Number of Retweets')
      plt.title('Number of Retweets Summary')
      plt.bar(tweets, num_retweets)
      plt.show()