How to use the mediafile.StorageStyle function in mediafile

def setUp(self):
        self.create_temp_dir()
        self.key = "READ_ONLY_TEST"
        self.field = mediafile.MediaField(
            mediafile.MP3StorageStyle(self.key, read_only=True),
            mediafile.MP4StorageStyle(
                "----:com.apple.iTunes:" + self.key, read_only=True),
            mediafile.StorageStyle(self.key, read_only=True),
            mediafile.ASFStorageStyle(self.key, read_only=True),
        )

        if "read_only_test" not in mediafile.MediaFile.fields():
            mediafile.MediaFile.add_field("read_only_test", self.field)

MP4StorageStyle('\xa9grp'),
        StorageStyle('GROUPING'),
        ASFStorageStyle('WM/ContentGroupDescription'),
    )
    track = MediaField(
        MP3SlashPackStorageStyle('TRCK', pack_pos=0),
        MP4TupleStorageStyle('trkn', index=0),
        StorageStyle('TRACK'),
        StorageStyle('TRACKNUMBER'),
        ASFStorageStyle('WM/TrackNumber'),
        out_type=int,
    )
    tracktotal = MediaField(
        MP3SlashPackStorageStyle('TRCK', pack_pos=1),
        MP4TupleStorageStyle('trkn', index=1),
        StorageStyle('TRACKTOTAL'),
        StorageStyle('TRACKC'),
        StorageStyle('TOTALTRACKS'),
        ASFStorageStyle('TotalTracks'),
        out_type=int,
    )
    disc = MediaField(
        MP3SlashPackStorageStyle('TPOS', pack_pos=0),
        MP4TupleStorageStyle('disk', index=0),
        StorageStyle('DISC'),
        StorageStyle('DISCNUMBER'),
        ASFStorageStyle('WM/PartOfSet'),
        out_type=int,
    )
    disctotal = MediaField(
        MP3SlashPackStorageStyle('TPOS', pack_pos=1),
        MP4TupleStorageStyle('disk', index=1),

)
    genre = MediaField(
        mp3 = StorageStyle('TCON'),
        mp4 = StorageStyle("\xa9gen"),
        etc = StorageStyle('GENRE'),
        asf = StorageStyle('WM/Genre'),
    )
    composer = MediaField(
        mp3 = StorageStyle('TCOM'),
        mp4 = StorageStyle("\xa9wrt"),
        etc = StorageStyle('COMPOSER'),
        asf = StorageStyle('WM/Composer'),
    )
    grouping = MediaField(
        mp3 = StorageStyle('TIT1'),
        mp4 = StorageStyle("\xa9grp"),
        etc = StorageStyle('GROUPING'),
        asf = StorageStyle('WM/ContentGroupDescription'),
    )
    track = MediaField(out_type=int,
        mp3 = StorageStyle('TRCK', packing=packing.SLASHED, pack_pos=0),
        mp4 = StorageStyle('trkn', packing=packing.TUPLE, pack_pos=0),
        etc = [StorageStyle('TRACK'),
               StorageStyle('TRACKNUMBER')],
        asf = StorageStyle('WM/TrackNumber'),
    )
    tracktotal = MediaField(out_type=int,
        mp3 = StorageStyle('TRCK', packing=packing.SLASHED, pack_pos=1),
        mp4 = StorageStyle('trkn', packing=packing.TUPLE, pack_pos=1),
        etc = [StorageStyle('TRACKTOTAL'),
               StorageStyle('TRACKC'),
               StorageStyle('TOTALTRACKS')],

StorageStyle('----:com.apple.iTunes:publisher')],
        etc = [StorageStyle('LABEL'),
               StorageStyle('PUBLISHER')],  # Traktor
        asf = StorageStyle('WM/Publisher'),
    )
    artist_sort = MediaField(
        mp3 = StorageStyle('TSOP'),
        mp4 = StorageStyle("soar"),
        etc = StorageStyle('ARTISTSORT'),
        asf = StorageStyle('WM/ArtistSortOrder'),
    )
    albumartist_sort = MediaField(
        mp3 = StorageStyle('TXXX', id3_desc=u'ALBUMARTISTSORT'),
        mp4 = StorageStyle("soaa"),
        etc = StorageStyle('ALBUMARTISTSORT'),
        asf = StorageStyle('WM/AlbumArtistSortOrder'),
    )
    asin = MediaField(
        mp3 = StorageStyle('TXXX', id3_desc=u'ASIN'),
        mp4 = StorageStyle("----:com.apple.iTunes:ASIN"),
        etc = StorageStyle('ASIN'),
        asf = StorageStyle('MusicBrainz/ASIN'),
    )
    catalognum = MediaField(
        mp3 = StorageStyle('TXXX', id3_desc=u'CATALOGNUMBER'),
        mp4 = StorageStyle("----:com.apple.iTunes:CATALOGNUMBER"),
        etc = StorageStyle('CATALOGNUMBER'),
        asf = StorageStyle('WM/CatalogNo'),
    )
    disctitle = MediaField(
        mp3 = StorageStyle('TSST'),
        mp4 = StorageStyle("----:com.apple.iTunes:DISCSUBTITLE"),

date = DateField(
        MP3StorageStyle('TDRC'),
        MP4StorageStyle('\xa9day'),
        StorageStyle('DATE'),
        ASFStorageStyle('WM/Year'),
        year=(StorageStyle('YEAR'),))

    year = date.year_field()
    month = date.month_field()
    day = date.day_field()

    # *Original* release date.
    original_date = DateField(
        MP3StorageStyle('TDOR'),
        MP4StorageStyle('----:com.apple.iTunes:ORIGINAL YEAR'),
        StorageStyle('ORIGINALDATE'),
        ASFStorageStyle('WM/OriginalReleaseYear'))

    original_year = original_date.year_field()
    original_month = original_date.month_field()
    original_day = original_date.day_field()

    # Nonstandard metadata.
    artist_credit = MediaField(
        MP3DescStorageStyle(u'Artist Credit'),
        MP4StorageStyle('----:com.apple.iTunes:Artist Credit'),
        StorageStyle('ARTIST_CREDIT'),
        ASFStorageStyle('beets/Artist Credit'),
    )
    albumartist_credit = MediaField(
        MP3DescStorageStyle(u'Album Artist Credit'),
        MP4StorageStyle('----:com.apple.iTunes:Album Artist Credit'),

mp4 = StorageStyle("\xa9cmt"),
        etc = [StorageStyle('DESCRIPTION'),
               StorageStyle('COMMENT')],
        asf = StorageStyle('WM/Comments'),
    )
    bpm = MediaField(out_type=int,
        mp3 = StorageStyle('TBPM'),
        mp4 = StorageStyle('tmpo', as_type=int),
        etc = StorageStyle('BPM'),
        asf = StorageStyle('WM/BeatsPerMinute'),
    )
    comp = MediaField(out_type=bool,
        mp3 = StorageStyle('TCMP'),
        mp4 = StorageStyle('cpil', list_elem=False, as_type=bool),
        etc = StorageStyle('COMPILATION'),
        asf = StorageStyle('WM/IsCompilation', as_type=bool),
    )
    albumartist = MediaField(
        mp3 = StorageStyle('TPE2'),
        mp4 = StorageStyle('aART'),
        etc = [StorageStyle('ALBUM ARTIST'),
               StorageStyle('ALBUMARTIST')],
        asf = StorageStyle('WM/AlbumArtist'),
    )
    albumtype = MediaField(
        mp3 = StorageStyle('TXXX', id3_desc=u'MusicBrainz Album Type'),
        mp4 = StorageStyle('----:com.apple.iTunes:MusicBrainz Album Type'),
        etc = StorageStyle('MUSICBRAINZ_ALBUMTYPE'),
        asf = StorageStyle('MusicBrainz/Album Type'),
    )
    label = MediaField(
        mp3 = StorageStyle('TPUB'),

mp4 = StorageStyle("----:com.apple.iTunes:Album Artist Credit"),
        etc = StorageStyle('ALBUMARTIST_CREDIT'),
        asf = StorageStyle('beets/Album Artist Credit'),
    )

    # Album art.
    art = ImageField()

    # MusicBrainz IDs.
    mb_trackid = MediaField(
        mp3 = StorageStyle('UFID:http://musicbrainz.org',
                            list_elem = False,
                            id3_frame_field = 'data'),
        mp4 = StorageStyle('----:com.apple.iTunes:MusicBrainz Track Id',
                           as_type=str),
        etc = StorageStyle('MUSICBRAINZ_TRACKID'),
        asf = StorageStyle('MusicBrainz/Track Id'),
    )
    mb_albumid = MediaField(
        mp3 = StorageStyle('TXXX', id3_desc=u'MusicBrainz Album Id'),
        mp4 = StorageStyle('----:com.apple.iTunes:MusicBrainz Album Id',
                           as_type=str),
        etc = StorageStyle('MUSICBRAINZ_ALBUMID'),
        asf = StorageStyle('MusicBrainz/Album Id'),
    )
    mb_artistid = MediaField(
        mp3 = StorageStyle('TXXX', id3_desc=u'MusicBrainz Artist Id'),
        mp4 = StorageStyle('----:com.apple.iTunes:MusicBrainz Artist Id',
                           as_type=str),
        etc = StorageStyle('MUSICBRAINZ_ARTISTID'),
        asf = StorageStyle('MusicBrainz/Artist Id'),
    )

MP3PeopleStorageStyle('TIPL', involvement='arranger'),
        MP4StorageStyle('----:com.apple.iTunes:Arranger'),
        StorageStyle('ARRANGER'),
        ASFStorageStyle('beets/Arranger'),
    )

    grouping = MediaField(
        MP3StorageStyle('TIT1'),
        MP4StorageStyle('\xa9grp'),
        StorageStyle('GROUPING'),
        ASFStorageStyle('WM/ContentGroupDescription'),
    )
    track = MediaField(
        MP3SlashPackStorageStyle('TRCK', pack_pos=0),
        MP4TupleStorageStyle('trkn', index=0),
        StorageStyle('TRACK'),
        StorageStyle('TRACKNUMBER'),
        ASFStorageStyle('WM/TrackNumber'),
        out_type=int,
    )
    tracktotal = MediaField(
        MP3SlashPackStorageStyle('TRCK', pack_pos=1),
        MP4TupleStorageStyle('trkn', index=1),
        StorageStyle('TRACKTOTAL'),
        StorageStyle('TRACKC'),
        StorageStyle('TOTALTRACKS'),
        ASFStorageStyle('TotalTracks'),
        out_type=int,
    )
    disc = MediaField(
        MP3SlashPackStorageStyle('TPOS', pack_pos=0),
        MP4TupleStorageStyle('disk', index=0),

MP4StorageStyle('----:com.apple.iTunes:MusicBrainz '
                        'Album Release Country'),
        StorageStyle('RELEASECOUNTRY'),
        ASFStorageStyle('MusicBrainz/Album Release Country'),
    )
    albumstatus = MediaField(
        MP3DescStorageStyle(u'MusicBrainz Album Status'),
        MP4StorageStyle('----:com.apple.iTunes:MusicBrainz Album Status'),
        StorageStyle('RELEASESTATUS'),
        StorageStyle('MUSICBRAINZ_ALBUMSTATUS'),
        ASFStorageStyle('MusicBrainz/Album Status'),
    )
    media = MediaField(
        MP3StorageStyle('TMED'),
        MP4StorageStyle('----:com.apple.iTunes:MEDIA'),
        StorageStyle('MEDIA'),
        ASFStorageStyle('WM/Media'),
    )
    albumdisambig = MediaField(
        # This tag mapping was invented for beets (not used by Picard, etc).
        MP3DescStorageStyle(u'MusicBrainz Album Comment'),
        MP4StorageStyle('----:com.apple.iTunes:MusicBrainz Album Comment'),
        StorageStyle('MUSICBRAINZ_ALBUMCOMMENT'),
        ASFStorageStyle('MusicBrainz/Album Comment'),
    )

    # Release date.
    date = DateField(
        MP3StorageStyle('TDRC'),
        MP4StorageStyle('\xa9day'),
        StorageStyle('DATE'),
        ASFStorageStyle('WM/Year'),

lyricist = MediaField(
        MP3StorageStyle('TEXT'),
        MP4StorageStyle('----:com.apple.iTunes:LYRICIST'),
        StorageStyle('LYRICIST'),
        ASFStorageStyle('WM/Writer'),
    )
    composer = MediaField(
        MP3StorageStyle('TCOM'),
        MP4StorageStyle('\xa9wrt'),
        StorageStyle('COMPOSER'),
        ASFStorageStyle('WM/Composer'),
    )
    composer_sort = MediaField(
        MP3StorageStyle('TSOC'),
        MP4StorageStyle('soco'),
        StorageStyle('COMPOSERSORT'),
        ASFStorageStyle('WM/Composersortorder'),
    )
    arranger = MediaField(
        MP3PeopleStorageStyle('TIPL', involvement='arranger'),
        MP4StorageStyle('----:com.apple.iTunes:Arranger'),
        StorageStyle('ARRANGER'),
        ASFStorageStyle('beets/Arranger'),
    )

    grouping = MediaField(
        MP3StorageStyle('TIT1'),
        MP4StorageStyle('\xa9grp'),
        StorageStyle('GROUPING'),
        ASFStorageStyle('WM/ContentGroupDescription'),
    )
    track = MediaField(