input: Write a function to visually summarize Twitter data stream. The Twitter data contains fields like tweet author, date of tweet, text, number of likes, and number of retweets. The function should process the data and plot summaries for tweet authors, number of likes, and number of retweets.
  
  import matplotlib.pyplot as plt
  
  def visualize_twitter_data(twitter_data):
      # Process the Twitter data to extract the relevant data fields
      authors = [tweet[0] for tweet in twitter_data]
      num_tweets = [authors.count(author) for author in set(authors)]
      tweets = [tweet[2] for tweet in twitter_data]
      num_likes = [tweet[3] for tweet in twitter_data]
      num_retweets = [tweet[4] for tweet in twitter_data]
      
      # Plot the tweet authors
      plt.xlabel('Tweet Authors')
      plt.ylabel('Number of tweets')
      plt.title('Tweet Author Summary')
      plt.bar(set(authors), num_tweets)
      plt.show()
      
      # Plot the number of likes
      plt.xlabel('Tweets')
      plt.ylabel('Number of Likes')
      plt.title('Number of Likes Summary')
      plt.bar(range(len(tweets)), num_likes)
      plt.show()
      
      # Plot the number of retweets
      plt.xlabel('Tweets')
      plt.ylabel('Number of Retweets')
      plt.title('Number of Retweets Summary')
      plt.bar(range(len(tweets)), num_retweets)
      plt.show()
  
  assert visualize_twitter_data([['user1', '2023-01-01', 'tweet1', 10, 5], ['user2', '2023-01-02', 'tweet2', 5, 3], ['user1', '2023-01-03', 'tweet3', 8, 4]]) is None
output: def visualize_twitter_data(twitter_data):
      authors = [tweet[0] for tweet in twitter_data]
      num_tweets = [authors.count(author) for author in set(authors)]
      tweets = [tweet[2] for tweet in twitter_data]
      num_likes = [tweet[3] for tweet in twitter_data]
      num_retweets = [tweet[4] for tweet in twitter_data]
      
      plt.xlabel('Tweet Authors')
      plt.ylabel('Number of tweets')
      plt.title('Tweet Author Summary')
      plt.bar(set(authors), num_tweets)
      plt.show()
      
      plt.xlabel('Tweets')
      plt.ylabel('Number of Likes')
      plt.title('Number of Likes Summary')
      plt.bar(range(len(tweets)), num_likes)
      plt.show()
      
      plt.xlabel('Tweets')
      plt.ylabel('Number of Retweets')
      plt.title('Number of Retweets Summary')
      plt.bar(range(len(tweets)), num_retweets)
      plt.show()