input: def replace_word_in_sentence(sentence: str, old_word: str, new_word: str) -> str:
      """Replace a given word in a sentence with another word.
  
      >>> replace_word_in_sentence("I love walking on the beach", "walking", "swimming")
      "I love swimming on the beach"
      """
      return sentence.replace(old_word, new_word)
output:     return sentence.replace(old_word, new_word)