code: def time_question_features(self, text):
          
          features = {}
  
          # A list of all words from the known sentences
          all_words = " ".join(self.positive + self.negative).split()
  
          # A list of the first word in each of the known sentence
          all_first_words = []
          for sentence in self.positive + self.negative:
              all_first_words.append(
                  sentence.split(' ', 1)[0]
              )
  
          for word in text.split():
              features['first_word({})'.format(word)] = (word in all_first_words)
  
          for word in text.split():
              features['contains({})'.format(word)] = (word in all_words)
  
          for letter in 'abcdefghijklmnopqrstuvwxyz':
              features['count({})'.format(letter)] = text.lower().count(letter)
              features['has({})'.format(letter)] = (letter in text.lower())
  
          return features
docs: Provide an analysis of significant features in the string.