apply_filters( 'post_playlist', string $output, array $attr, int $instance )

3091	 * @since 4.2.0 The `$instance` parameter was added.3092	 *3093	 * @param string $output   Playlist output. Default empty.3094	 * @param array  $attr     An array of shortcode attributes.3095	 * @param int    $instance Unique numeric ID of this playlist shortcode instance.3096	 */3097	$output = apply_filters( 'post_playlist', '', $attr, $instance );3098 3099	if ( ! empty( $output ) ) {3100		return $output;3101	}3102 3103	$atts = shortcode_atts(