input: from typing import List
  
  def reverse_words_order(sentence: str) -> str:
      """ Reverse the order of words in a sentence while keeping the order of characters in each word unchanged.
      >>> reverse_words_order('This is a sentence.')
      'sentence. a is This'
      >>> reverse_words_order('Python is fun')
      'fun is Python'
      """
      words = sentence.split(" ")
      reversed_words = words[::-1]
      return ' '.join(reversed_words)
output:     words = sentence.split(" ")
      reversed_words = words[::-1]
      return ' '.join(reversed_words)