code: def add_episode(self, text, text_format, title, author, summary=None,
                      publish_date=None, synthesizer='watson', synth_args=None, sentence_break='. '):
          
          if title in self.episodes:
              raise ValueError('"' + title + '" already exists as an episode title.')
  
          link = self.output_path + '/' + title.replace(' ', '_').lower() + '.mp3'
          episode_text = convert_to_ssml(text, text_format)
          new_episode = Episode(episode_text, text_format, title, author, link, summary, publish_date, synthesizer, synth_args, sentence_break)
  
          self.episodes[title] = new_episode
docs: Add a new episode to the podcast.
  
          :param text:
              See :meth:`Episode`.
          :param text_format:
              See :meth:`Episode`.
          :param title:
              See :meth:`Episode`.
          :param author:
              See :meth:`Episode`.
          :param summary:
              See :meth:`Episode`.
          :param publish_date:
              See :meth:`Episode`.
          :param synthesizer:
              See :meth:`typecaster.utils.text_to_speech`.
          :param synth_args:
              See :meth:`typecaster.utils.text_to_speech`.
          :param sentence_break:
              See :meth:`typecaster.utils.text_to_speech`.