def import_tracks(self, import_tracks):
        """
        Add the given tracks/track to the corpus.
        If any of the given track-ids already exists, a suffix is appended so it is unique.

        Args:
            import_tracks (list): Either a list of or a single :py:class:`audiomate.tracks.Track`.

        Returns:
            dict: A dictionary containing track-idx mappings (old-track-idx/track-instance).
                  If a track is imported, whose idx already exists this mapping can be used to check
                  the new id.
        """

        if isinstance(import_tracks, tracks.Track):
            import_tracks = [import_tracks]

        idx_mapping = {}

        for track in import_tracks:
            idx_mapping[track.idx] = track

            # Add index to idx if already existing
            if track.idx in self._tracks.keys():
                track.idx = naming.index_name_if_in_list(track.idx, self._tracks.keys())

            self._tracks[track.idx] = track

        return idx_mapping
Add the given tracks/track to the corpus.
        If any of the given track-ids already exists, a suffix is appended so it is unique.

        Args:
            import_tracks (list): Either a list of or a single :py:class:`audiomate.tracks.Track`.

        Returns:
            dict: A dictionary containing track-idx mappings (old-track-idx/track-instance).
                  If a track is imported, whose idx already exists this mapping can be used to check
                  the new id.