Geoff Appleby
--- a/core/lib/Drupal/Core/Ajax/AddCssCommand.php
+++ b/core/lib/Drupal/Core/Ajax/AddCssCommand.php
   */
  protected $styles;

  /**
   * Constructs an AddCssCommand.
   *
-   * @param string[][]|string $styles
+   * @param string[][] $styles
   *   Arrays containing attributes of the stylesheets to be added to the page.
   *   i.e. `['href' => 'someURL']` becomes `<link href="someURL">`.
   */
-  public function __construct($styles) {
-    if (is_string($styles)) {
-      @trigger_error('The ' . __NAMESPACE__ . '\AddCssCommand with a string argument is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. See http://www.drupal.org/node/3154948', E_USER_DEPRECATED);
-    }
+  public function __construct(array $styles) {
-  public function __construct(array $styles) {
+  public function __construct(array $styles): void {