diff --git a/core/tests/Drupal/Tests/Core/DependencyInjection/Fixture/BarClass.php b/core/tests/Drupal/Tests/Core/DependencyInjection/Fixture/BarClass.php
index 8e10adb..bec5d88 100644
--- a/core/tests/Drupal/Tests/Core/DependencyInjection/Fixture/BarClass.php
+++ b/core/tests/Drupal/Tests/Core/DependencyInjection/Fixture/BarClass.php
@@ -2,23 +2,44 @@
 
 /**
  * @file
- * A stub class for use with ContainerBuilderTest.
- *
- * @see Drupal\Tests\Core\DependencyInjection\ContainerBuilderTest
+ * Contains \Drupal\Tests\Core\DependencyInjection\Fixture\BarClass.
  */
 
 namespace Drupal\Tests\Core\DependencyInjection\Fixture;
 
+/**
+ * Stub class which acts as a service to test the container.
+ *
+ * @see \Drupal\Tests\Core\DependencyInjection\ContainerBuilderTest
+ * @see \Drupal\Tests\Core\DependencyInjection\Fixture\BazClass
+ */
 class BarClass {
 
+  /**
+   * Storage for a protected BazClass object.
+   *
+   * @var Drupal\Tests\Core\DependencyInjection\Fixture\BazClass
+   */
   protected $baz;
 
-  public $foo = 'foo';
-
+  /**
+   * Setter for our BazClass object.
+   *
+   * This method is called during the service initialization.
+   *
+   * @param \Drupal\Tests\Core\DependencyInjection\Fixture\BazClass $baz
+   *   A BazClass object to store.
+   */
   public function setBaz(BazClass $baz) {
     $this->baz = $baz;
   }
 
+  /**
+   * Getter for our BazClass object.
+   *
+   * @return \Drupal\Tests\Core\DependencyInjection\Fixture\BazClass
+   *   The stored BazClass object.
+   */
   public function getBaz() {
     return $this->baz;
   }
diff --git a/core/tests/Drupal/Tests/Core/DependencyInjection/Fixture/BazClass.php b/core/tests/Drupal/Tests/Core/DependencyInjection/Fixture/BazClass.php
index 1087a7e..361b4a8 100644
--- a/core/tests/Drupal/Tests/Core/DependencyInjection/Fixture/BazClass.php
+++ b/core/tests/Drupal/Tests/Core/DependencyInjection/Fixture/BazClass.php
@@ -2,35 +2,17 @@
 
 /**
  * @file
- * A stub class for use with ContainerBuilderTest.
- *
- * @see Drupal\Tests\Core\DependencyInjection\ContainerBuilderTest
+ * Contains \Drupal\Tests\Core\DependencyInjection\Fixture\BazClass.
  */
 
 namespace Drupal\Tests\Core\DependencyInjection\Fixture;
 
+/**
+ * Stub class which acts as a service dependency, to test the container.
+ *
+ * @see \Drupal\Tests\Core\DependencyInjection\ContainerBuilderTest
+ * @see \Drupal\Tests\Core\DependencyInjection\Fixture\BarClass
+ */
 class BazClass {
 
-  protected $foo;
-
-  public function setFoo(Foo $foo) {
-    $this->foo = $foo;
-  }
-
-  public function configure($instance) {
-    $instance->configure();
-  }
-
-  public static function getInstance() {
-    return new self();
-  }
-
-  public static function configureStatic($instance) {
-    $instance->configure();
-  }
-
-  public static function configureStatic1() {
-
-  }
-
 }