Issue #3456311 by jonathanshaw, mxh: Make LazyPluginCollection::getIterator...

Issue #3456311 by jonathanshaw, mxh: Make LazyPluginCollection::getIterator more flexible, return a Traversable

core/.phpstan-baseline.php

@@ -1051,12 +1051,6 @@
 	'count' => 1,
 	'path' => __DIR__ . '/lib/Drupal/Component/Plugin/LazyPluginCollection.php',
 ];
-$ignoreErrors[] = [
-	'message' => '#^Method Drupal\\\\Component\\\\Plugin\\\\LazyPluginCollection\\:\\:getIterator\\(\\) return type with generic class ArrayIterator does not specify its types\\: TKey, TValue$#',
-	'identifier' => 'missingType.generics',
-	'count' => 1,
-	'path' => __DIR__ . '/lib/Drupal/Component/Plugin/LazyPluginCollection.php',
-];
 $ignoreErrors[] = [
 	'message' => '#^Method Drupal\\\\Component\\\\Plugin\\\\LazyPluginCollection\\:\\:initializePlugin\\(\\) has no return type specified\\.$#',
 	'identifier' => 'missingType.return',

core/lib/Drupal/Component/Plugin/LazyPluginCollection.php

@@ -142,7 +142,11 @@ public function removeInstanceId($instance_id) {
     $this->remove($instance_id);
   }
 
-  public function getIterator(): \ArrayIterator {
+  /**
+   * @return \Traversable<string, mixed>
+   *   A traversable generator.
+   */
+  public function getIterator(): \Traversable {
     $instances = [];
     foreach ($this->getInstanceIds() as $instance_id) {
       $instances[$instance_id] = $this->get($instance_id);