input: Write a function to determine if a given sentence is an 'affirmative' sentence or a 'negative' sentence. The function should utilize negation words to decide the nature of the sentence. To achieve this, the function should tokenize the sentence and check for any presence of negation words. If no negation words are found, the sentence is classified as 'affirmative'; otherwise, it is classified as 'negative'. If the input sentence is empty, the function should return 'Affirmative'.
  assert isAffirmativeorNegative("He always comes late but I dont mind.") == "Negative"
  assert isAffirmativeorNegative("She will definitely come.") == "Affirmative"
  assert isAffirmativeorNegative("No one knows about this.") == "Negative"
  assert isAffirmativeorNegative("") == "Affirmative"
output: def isAffirmativeorNegative(sentence):
      negation_words = ["not", "no", "never", "none", "nobody", "nothing", "neither", "nor", "nowhere", "hardly", "scarcely", "barely", "don't", "doesn't", "didn't", "isn't", "aren't", "wasn't", "weren't", "can't", "couldn't", "shouldn't", "wouldn't", "won't", "mustn't"]
      if not sentence:
          return "Affirmative"
      tokens = sentence.lower().split()
      for word in tokens:
          if word in negation_words:
              return "Negative"
      return "Affirmative"