WP_Widget_Media::_register_one

	public function _register_one( $number = -1 ) {
		parent::_register_one( $number );
		if ( $this->registered ) {
			return;
		}
		$this->registered = true;

		// Note that the widgets component in the customizer will also do
		// the 'admin_print_scripts-widgets.php' action in WP_Customize_Widgets::print_scripts().
		add_action( 'admin_print_scripts-widgets.php', array( $this, 'enqueue_admin_scripts' ) );

		if ( $this->is_preview() ) {
			add_action( 'wp_enqueue_scripts', array( $this, 'enqueue_preview_scripts' ) );
		}

		// Note that the widgets component in the customizer will also do
		// the 'admin_footer-widgets.php' action in WP_Customize_Widgets::print_footer_scripts().
		add_action( 'admin_footer-widgets.php', array( $this, 'render_control_template_scripts' ) );

		add_filter( 'display_media_states', array( $this, 'display_media_state' ), 10, 2 );
	}