input: def reverse_order_of_words(sentence: str) -> str:
      """ Reverses the order of words in a given sentence while keeping the characters in each word in the same order.
      >>> reverse_order_of_words('This is a sentence.')
      'sentence. a is This'
      >>> reverse_order_of_words('Hello world!')
      'world! Hello'
      """
      words = sentence.split(" ")
      reversed_words = words[::-1]
      return ' '.join(reversed_words)
output:     words = sentence.split(" ")
      reversed_words = words[::-1]
      return ' '.join(reversed_words)