docs: def addTrack(self, track):
          """
          Add a track to be recorded.
  
          :param: track: An :class:`aiortc.AudioStreamTrack` or :class:`aiortc.VideoStreamTrack`.
          """
          if track.kind == 'audio':
              if self.__container.format.name == 'wav':
                  codec_name = 'pcm_s16le'
              elif self.__container.format.name == 'mp3':
                  codec_name = 'mp3'
              else:
                  codec_name = 'aac'
              stream = self.__container.add_stream(codec_name)
          else:
              if self.__container.format.name == 'image2':
                  stream = self.__container.add_stream('png', rate=30)
                  stream.pix_fmt = 'rgb24'
              else:
                  stream = self.__container.add_stream('libx264', rate=30)
                  stream.pix_fmt = 'yuv420p'
          self.__tracks[track] = MediaRecorderContext(stream)