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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def add_tracks(self, track):
 """ Add a track or iterable of tracks. Parameters track : iterable or Track Iterable of :class:`Track` objects, or a single :class:`Track` object. """

        from trackhub import BaseTrack
        if isinstance(track, BaseTrack):
            self.add_child(track)
            self._tracks.append(track)
        else:
            for t in track:
                self.add_child(t)
                self._tracks.append(t)