input: Write a function to visually summarize the Twitter data. The function should process the Twitter data to extract relevant fields such as tweet author, date of tweet, text, number of likes, and number of retweets, and then plot summaries using matplotlib. The function should return None.
  
  import matplotlib.pyplot as plt
  
  def summarize_twitter_data(twitter_data):
      # Process the Twitter data to extract
      # the relevant data fields
      # ...
  
      # Plot the tweet authors
      plt.xlabel('Tweet Authors')
      plt.ylabel('Number of tweets')
      plt.title('Tweet Author Summary')
      plt.bar(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(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(tweets, num_retweets)
      plt.show()
      
      return None
  
  assert summarize_twitter_data(example_twitter_data) == None
output: import matplotlib.pyplot as plt
  
  def summarize_twitter_data(twitter_data):
      authors = [tweet['author'] for tweet in twitter_data]
      dates = [tweet['date'] for tweet in twitter_data]
      texts = [tweet['text'] for tweet in twitter_data]
      likes = [tweet['likes'] for tweet in twitter_data]
      retweets = [tweet['retweets'] for tweet in twitter_data]
      
      author_counts = {author: authors.count(author) for author in set(authors)}
      authors_list = list(author_counts.keys())
      num_tweets = list(author_counts.values())
      
      plt.figure(1)
      plt.xlabel('Tweet Authors')
      plt.ylabel('Number of tweets')
      plt.title('Tweet Author Summary')
      plt.bar(authors_list, num_tweets)
      plt.xticks(rotation=45)
      plt.show()
  
      plt.figure(2)
      plt.xlabel('Tweets')
      plt.ylabel('Number of Likes')
      plt.title('Number of Likes Summary')
      plt.bar(texts, likes)
      plt.xticks(rotation=90)
      plt.show()
  
      plt.figure(3)
      plt.xlabel('Tweets')
      plt.ylabel('Number of Retweets')
      plt.title('Number of Retweets Summary')
      plt.bar(texts, retweets)
      plt.xticks(rotation=90)
      plt.show()
      
      return None