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

3066	 * @since 4.2.0 The `$instance` parameter was added.3067	 *3068	 * @param string $output   Playlist output. Default empty.3069	 * @param array  $attr     An array of shortcode attributes.3070	 * @param int    $instance Unique numeric ID of this playlist shortcode instance.3071	 */3072	$output = apply_filters( 'post_playlist', '', $attr, $instance );3073 3074	if ( ! empty( $output ) ) {3075		return $output;3076	}3077 3078	$atts = shortcode_atts(