input: Write a python function to summarize an article by including sentences that contain specific keywords such as 'imagination' or 'inventiveness'.
  assert summarize_article("Einstein once said that “imagination is more important than knowledge”. According to his famous quote, in order to truly move forward and make an impact on the world, one should use creativity and inventiveness to push boundaries. Knowledge is limited while imagination embraces the entire world.") == "Einstein once said that “imagination is more important than knowledge”. According to his famous quote, in order to truly move forward and make an impact on the world, one should use creativity and inventiveness to push boundaries."
  assert summarize_article("The power of imagination is often underestimated. Inventiveness has led to many of the world's greatest inventions. Ordinary people can achieve extraordinary things through imagination.") == "The power of imagination is often underestimated. Inventiveness has led to many of the world's greatest inventions."
  assert summarize_article("Creativity is a valuable asset. Logical thinking is essential for problem-solving.") == ""
output: def summarize_article(article):
      keywords = {'imagination', 'inventiveness'}
      sentences = article.split('. ')
      summary = []
      
      for sentence in sentences:
          if any(keyword in sentence for keyword in keywords):
              summary.append(sentence)
      
      return '. '.join(summary)