diff --git a/src/PluginDefinition/ArrayPluginDefinitionDecorator.php b/src/PluginDefinition/ArrayPluginDefinitionDecorator.php
index b7c55db..2ce5829 100644
--- a/src/PluginDefinition/ArrayPluginDefinitionDecorator.php
+++ b/src/PluginDefinition/ArrayPluginDefinitionDecorator.php
@@ -89,13 +89,20 @@ class ArrayPluginDefinitionDecorator implements ArrayPluginDefinitionInterface,
   /**
    * {@inheritdoc}
    */
-  public function getId() {
+  public function id() {
     return isset($this->arrayDefinition['id']) ? $this->arrayDefinition['id'] : NULL;
   }
 
   /**
    * {@inheritdoc}
    */
+  public function getId() {
+    return $this->id();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
   public function setClass($class) {
     PluginDefinitionValidator::validateClass($class);
 
diff --git a/tests/src/Unit/Controller/ListPluginTypesTest.php b/tests/src/Unit/Controller/ListPluginTypesTest.php
index ac7830d..a1579b2 100644
--- a/tests/src/Unit/Controller/ListPluginTypesTest.php
+++ b/tests/src/Unit/Controller/ListPluginTypesTest.php
@@ -9,7 +9,7 @@ use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\plugin\Controller\ListPluginTypes;
 use Drupal\plugin\PluginType\PluginType;
 use Drupal\plugin\PluginType\PluginTypeManagerInterface;
-use Drupal\Tests\plugin\TranslationMock;
+use Drupal\Tests\plugin\Unit\TranslationMock;
 use Drupal\Tests\UnitTestCase;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
diff --git a/tests/src/TranslationMock.php b/tests/src/Unit/TranslationMock.php
similarity index 97%
rename from tests/src/TranslationMock.php
rename to tests/src/Unit/TranslationMock.php
index 4748b0e..51adc5a 100644
--- a/tests/src/TranslationMock.php
+++ b/tests/src/Unit/TranslationMock.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Drupal\Tests\plugin;
+namespace Drupal\Tests\plugin\Unit;
 
 use Drupal\Component\Utility\SafeMarkup;
 use Drupal\Core\StringTranslation\TranslatableMarkup;