wp_dashboard_rss_control

function wp_dashboard_rss_output( $widget_id ) {
	$widgets = get_option( 'dashboard_widget_options' );
	echo '<div class="rss-widget">';
	wp_widget_rss_output( $widgets[ $widget_id ] );
	echo '</div>';
}

/**
 * Checks to see if all of the feed url in $check_urls are cached.
 *
 * If $check_urls is empty, look for the rss feed url found in the dashboard
 * widget options of $widget_id. If cached, call $callback, a function that
 * echoes out output for this widget. If not cache, echo a "Loading..." stub
 * which is later replaced by Ajax call (see top of /wp-admin/index.php)
 *
 * @since 2.5.0
 * @since 5.3.0 Formalized the existing and already documented `...$args` parameter
 *              by adding it to the function signature.
 *
 * @param string   $widget_id  The widget ID.
 * @param callable $callback   The callback function used to display each feed.
 * @param array    $check_urls RSS feeds.
 * @param mixed    ...$args    Optional additional parameters to pass to the callback function.
 * @return bool True on success, false on failure.
 */
function wp_dashboard_cached_rss_widget( $widget_id, $callback, $check_urls = array(), ...$args ) {
	$loading    = '<p class="widget-loading hide-if-no-js">' . __( 'Loading&hellip;' ) . '</p><div class="hide-if-js notice notice-error inline"><p>' . __( 'This widget requires JavaScript.' ) . '</p></div>';
	$doing_ajax = wp_doing_ajax();

	if ( empty( $check_urls ) ) {
		$widgets = get_option( 'dashboard_widget_options' );
		if ( empty( $widgets[ $widget_id ]['url'] ) && ! $doing_ajax ) {
			echo $loading;
			return false;
		}
		$check_urls = array( $widgets[ $widget_id ]['url'] );