Fix spelling

src/View/BlockViewBuilder.php

@@ -135,7 +135,7 @@ class BlockViewBuilder {
       if ($block_plugin instanceof TitleBlockPluginInterface) {
         $build['content']['#cache']['contexts'][] = 'url';
       }
-      // Some blocks returns NULL instead of array when empty.
+      // Some blocks return null instead of array when empty.
       // @see https://www.drupal.org/project/drupal/issues/3212354
       if ($wrapper && is_array($build['content']) && !Element::isEmpty($build['content'])) {
         $build += [