code: def create(self, mention, max_message_length):
          
          message = []
  
          def message_len():
              return sum([len(w) + 1 for w in message])
  
          while message_len() < max_message_length:
              message.append(self.a_random_word(message[-1] if message else None))
  
          return ' '.join(message[:-1])
docs: Create a message
          :param mention: JSON object containing mention details from Twitter (or an empty dict {})
          :param max_message_length: Maximum allowable length for created message
          :return: A random message created using a Markov chain generator