input: from typing import List
  
  def sentiment_analysis(tweets: List[str]) -> List[str]:
      """Analyzes the sentiment of a list of tweets and returns a list of sentiment labels.
      
      ### Example:
      >>> sentiment_analysis(["I love this product!", "I hate waiting in line."])
      ['Positive', 'Negative']
      >>> sentiment_analysis(["Great day today!", "Not sure how I feel."])
      ['Positive', 'Negative']
      """
      results = []
      for tweet in tweets:
          tweet = preprocessing(tweet)
          tweet_vector = vectorize(tweet)
          prediction = predict_sentiment(tweet_vector)
          
          if prediction == 1:
              results.append("Positive")
          elif prediction == 0:
              results.append("Negative")
  
      return results
output:     results = []
      for tweet in tweets:
          tweet = preprocessing(tweet)
          tweet_vector = vectorize(tweet)
          prediction = predict_sentiment(tweet_vector)
          
          if prediction == 1:
              results.append("Positive")
          elif prediction == 0:
              results.append("Negative")
  
      return results