How to use the beets.ui.colordiff function in beets

def show_item_change(item, match):
    """Print out the change that would occur by tagging `item` with the
    metadata from `match`, a TrackMatch object.
    """
    cur_artist, new_artist = item.artist, match.info.artist
    cur_title, new_title = item.title, match.info.title

    if cur_artist != new_artist or cur_title != new_title:
        cur_artist, new_artist = ui.colordiff(cur_artist, new_artist)
        cur_title, new_title = ui.colordiff(cur_title, new_title)

        print_("Correcting track tags from:")
        print_("    %s - %s" % (cur_artist, cur_title))
        print_("To:")
        print_("    %s - %s" % (new_artist, new_title))

    else:
        print_("Tagging track: %s - %s" % (cur_artist, cur_title))

    # Data URL.
    if match.info.data_url:
        print_('URL:\n    %s' % match.info.data_url)

    # Info line.
    info = []
    # Similarity.

lhs = '%s: %s' % (media, track_info.disctitle)
            else:
                lhs = None
            if lhs:
                lines.append((lhs, '', 0))
            medium, disctitle = track_info.medium, track_info.disctitle

        # Titles.
        new_title = track_info.title
        if not item.title.strip():
            # If there's no title, we use the filename.
            cur_title = displayable_path(os.path.basename(item.path))
            lhs, rhs = cur_title, new_title
        else:
            cur_title = item.title.strip()
            lhs, rhs = ui.colordiff(cur_title, new_title)
        lhs_width = len(cur_title)

        # Track number change.
        cur_track, new_track = format_index(item), format_index(track_info)
        if cur_track != new_track:
            if item.track in (track_info.index, track_info.medium_index):
                color = 'lightgray'
            else:
                color = 'red'
            if (cur_track + new_track).count('-') == 1:
                lhs_track, rhs_track = ui.colorize(color, cur_track), \
                                       ui.colorize(color, new_track)
            else:
                color = 'red'
                lhs_track, rhs_track = ui.color_diff_suffix(cur_track,
                                                            new_track)

lhs = '%s: %s' % (media, track_info.disctitle)
            else:
                lhs = None
            if lhs:
                lines.append((lhs, '', 0))
            medium, disctitle = track_info.medium, track_info.disctitle

        # Titles.
        new_title = track_info.title
        if not item.title.strip():
            # If there's no title, we use the filename.
            cur_title = displayable_path(os.path.basename(item.path))
            lhs, rhs = cur_title, new_title
        else:
            cur_title = item.title.strip()
            lhs, rhs = ui.colordiff(cur_title, new_title)
        lhs_width = len(cur_title)

        # Track number change.
        cur_track, new_track = format_index(item), format_index(track_info)
        if cur_track != new_track:
            if item.track in (track_info.index, track_info.medium_index):
                color = 'lightgray'
            else:
                color = 'red'
            if (cur_track + new_track).count('-') == 1:
                lhs_track, rhs_track = (ui.colorize(color, cur_track),
                                        ui.colorize(color, new_track))
            else:
                color = 'red'
                lhs_track, rhs_track = ui.color_diff_suffix(cur_track,
                                                            new_track)

def show_item_change(item, match):
    """Print out the change that would occur by tagging `item` with the
    metadata from `match`, a TrackMatch object.
    """
    cur_artist, new_artist = item.artist, match.info.artist
    cur_title, new_title = item.title, match.info.title

    if cur_artist != new_artist or cur_title != new_title:
        cur_artist, new_artist = ui.colordiff(cur_artist, new_artist)
        cur_title, new_title = ui.colordiff(cur_title, new_title)

        print_(u"Correcting track tags from:")
        print_(u"    %s - %s" % (cur_artist, cur_title))
        print_(u"To:")
        print_(u"    %s - %s" % (new_artist, new_title))

    else:
        print_(u"Tagging track: %s - %s" % (cur_artist, cur_title))

    # Data URL.
    if match.info.data_url:
        print_(u'URL:\n    %s' % match.info.data_url)

    # Info line.
    info = []
    # Similarity.

else:
                return unicode(medium_index)
        else:
            return unicode(index)

    # Identify the album in question.
    if cur_artist != match.info.artist or \
            (cur_album != match.info.album and
             match.info.album != VARIOUS_ARTISTS):
        artist_l, artist_r = cur_artist or '', match.info.artist
        album_l,  album_r  = cur_album  or '', match.info.album
        if artist_r == VARIOUS_ARTISTS:
            # Hide artists for VA releases.
            artist_l, artist_r = u'', u''

        artist_l, artist_r = ui.colordiff(artist_l, artist_r)
        album_l, album_r   = ui.colordiff(album_l, album_r)

        print_("Correcting tags from:")
        show_album(artist_l, album_l)
        print_("To:")
        show_album(artist_r, album_r)
    else:
        print_(u"Tagging:\n    {0.artist} - {0.album}".format(match.info))

    # Data URL.
    if match.info.data_url:
        print_('URL:\n    %s' % match.info.data_url)

    # Info line.
    info = []
    # Similarity.

def show_item_change(item, match):
    """Print out the change that would occur by tagging `item` with the
    metadata from `match`, a TrackMatch object.
    """
    cur_artist, new_artist = item.artist, match.info.artist
    cur_title, new_title = item.title, match.info.title

    if cur_artist != new_artist or cur_title != new_title:
        cur_artist, new_artist = ui.colordiff(cur_artist, new_artist)
        cur_title, new_title = ui.colordiff(cur_title, new_title)

        print_("Correcting track tags from:")
        print_("    %s - %s" % (cur_artist, cur_title))
        print_("To:")
        print_("    %s - %s" % (new_artist, new_title))

    else:
        print_("Tagging track: %s - %s" % (cur_artist, cur_title))

    # Data URL.
    if match.info.data_url:
        print_('URL:\n    %s' % match.info.data_url)

    # Info line.
    info = []

lhs = u'%s: %s' % (media, track_info.disctitle)
            else:
                lhs = None
            if lhs:
                lines.append((lhs, u'', 0))
            medium, disctitle = track_info.medium, track_info.disctitle

        # Titles.
        new_title = track_info.title
        if not item.title.strip():
            # If there's no title, we use the filename.
            cur_title = displayable_path(os.path.basename(item.path))
            lhs, rhs = cur_title, new_title
        else:
            cur_title = item.title.strip()
            lhs, rhs = ui.colordiff(cur_title, new_title)
        lhs_width = len(cur_title)

        # Track number change.
        cur_track, new_track = format_index(item), format_index(track_info)
        if cur_track != new_track:
            if item.track in (track_info.index, track_info.medium_index):
                color = 'text_highlight_minor'
            else:
                color = 'text_highlight'
            templ = ui.colorize(color, u' (#{0})')
            lhs += templ.format(cur_track)
            rhs += templ.format(new_track)
            lhs_width += len(cur_track) + 4

        # Length change.
        if item.length and track_info.length and \