input: Write a function to identify whether a given sentence is an 'affirmative' sentence or a 'negative' sentence. If the sentence contains negation words, it should be identified as 'Negative'; otherwise, it should be identified as 'Affirmative'. If the sentence is empty, it should be considered 'Affirmative'.
  assert isAffirmativeorNegative("He always comes late but I dont mind.") == "Negative"
  assert isAffirmativeorNegative("She will be there tomorrow.") == "Affirmative"
  assert isAffirmativeorNegative("Nobody said anything.") == "Negative"
  assert isAffirmativeorNegative("") == "Affirmative"
output: def isAffirmativeorNegative(sentence):
      negation_words = ["not", "no", "never", "none", "nobody", "nothing", "neither", "nowhere", "hardly", "scarcely", "barely", "dont", "doesnt", "didnt", "wont", "wouldnt", "cant", "couldnt", "shouldnt", "isnt", "arent", "wasnt", "werent"]
      if not sentence:
          return "Affirmative"
      for word in negation_words:
          if word in sentence.lower():
              return "Negative"
      return "Affirmative"