input: 
  def reverse_words(string: str) -> str:
      """
      This function takes a given string and reverses the order of its words.
      
      Examples:
      >>> reverse_words("Hello world")
      'world Hello'
      >>> reverse_words("Python is fun")
      'fun is Python'
      """
      return " ".join(string.split()[::-1])
  
output:     words = string.split()
      reversed_words = words[::-1]
      return " ".join(reversed_words)