code: def __trim_outputspeech(self, speech_output=None):
          # type: (Union[str, None]) -> str
          
          if speech_output is None:
              return ""
          speech = speech_output.strip()
          if speech.startswith("<speak>") and speech.endswith("</speak>"):
              return speech[7:-8].strip()
          return speech
docs: Trims the output speech if it already has the
          <speak></speak> tag.
  
          :param speech_output: the output speech sent back to user.
          :type speech_output: str
          :return: the trimmed output speech.
          :rtype: Union[bool, None]