*
	 * @return void
	 */
	public function __construct() {

		// Allow child classes to configure variables.
		$this->configure();

		// Set the error option key.
		$this->error_opt_key = sprintf( 'lifterlms_metabox_errors%s', $this->id );

		// Register the metabox.
		add_action( 'add_meta_boxes', array( $this, 'register' ) );

		// Register save actions for applicable screens (post types).
		foreach ( $this->get_screens() as $screen ) {
			add_action( 'save_post_' . $screen, array( $this, 'save_actions' ), 10, 1 );
		}

		// Display errors.
		add_action( 'admin_notices', array( $this, 'output_errors' ) );

		// Save errors.