diff --git a/core/tests/Drupal/Tests/Core/Block/BlockManagerTest.php b/core/tests/Drupal/Tests/Core/Block/BlockManagerTest.php
index 87728c64ca..01eeb9af4e 100644
--- a/core/tests/Drupal/Tests/Core/Block/BlockManagerTest.php
+++ b/core/tests/Drupal/Tests/Core/Block/BlockManagerTest.php
@@ -46,6 +46,9 @@ protected function setUp(): void {
     $this->logger = $this->prophesize(LoggerInterface::class);
     $this->blockManager = new BlockManager(new \ArrayObject(), $cache_backend->reveal(), $module_handler->reveal(), $this->logger->reveal());
     $this->blockManager->setStringTranslation($this->getStringTranslationStub());
+
+    // Specify the 'broken' block, as well as 3 other blocks with admin labels
+    // that are purposefully not in alphabetical order.
     $this->setDefinitions([
       'broken' => [
         'admin_label' => 'Broken/Missing',
@@ -79,8 +82,6 @@ protected function setUp(): void {
    */
   protected function setDefinitions(array $definitions) {
     $discovery = $this->prophesize(DiscoveryInterface::class);
-    // Specify the 'broken' block, as well as 3 other blocks with admin labels
-    // that are purposefully not in alphabetical order.
     $discovery->getDefinitions()->willReturn($definitions);
     // Force the discovery object onto the block manager.
     $property = new \ReflectionProperty(BlockManager::class, 'discovery');
@@ -128,6 +129,8 @@ public function testHandlePluginNotFound() {
    * @expectedDeprecation Declaring ::build() without an array return typehint in Drupal\Tests\Core\Block\TestBlockManagerNoArrayReturnTypeBlock is deprecated in drupal:9.1.0. Typehinting will be required before drupal:10.0.0. See https://www.drupal.org/node/3164649.
    */
   public function testBuildNoReturnType() {
+    // Overwrite the definitions from ::setUp() to have a block thagt does not
+    // have a return type for ::build().
     $this->setDefinitions([
       'block1' => [
         'provider' => 'test',