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

3109	 * @since 4.2.0 The `$instance` parameter was added.3110	 *3111	 * @param string $output   Playlist output. Default empty.3112	 * @param array  $attr     An array of shortcode attributes.3113	 * @param int    $instance Unique numeric ID of this playlist shortcode instance.3114	 */3115	$output = apply_filters( 'post_playlist', '', $attr, $instance );3116 3117	if ( ! empty( $output ) ) {3118		return $output;3119	}3120 3121	$atts = shortcode_atts(