diff --git a/core/tests/Drupal/Tests/Core/DrupalTest.php b/core/tests/Drupal/Tests/Core/DrupalTest.php
index 7fb3719..134690f 100644
--- a/core/tests/Drupal/Tests/Core/DrupalTest.php
+++ b/core/tests/Drupal/Tests/Core/DrupalTest.php
@@ -52,7 +52,7 @@ public function testSetContainer() {
    */
   public function testService() {
     $this->setMockContainerService('test_service');
-    \Drupal::service('test_service');
+    $this->assertNotNull(\Drupal::service('test_service'));
   }
 
   /**
@@ -60,7 +60,7 @@ public function testService() {
    */
   public function testRequest() {
     $this->setMockContainerService('request');
-    \Drupal::request();
+    $this->assertNotNull(\Drupal::request());
   }
 
   /**
@@ -68,7 +68,7 @@ public function testRequest() {
    */
   public function testCurrentUser() {
     $this->setMockContainerService('current_user');
-    \Drupal::currentUser();
+    $this->assertNotNull(\Drupal::currentUser());
   }
 
   /**
@@ -76,7 +76,7 @@ public function testCurrentUser() {
    */
   public function testEntityManager() {
     $this->setMockContainerService('entity.manager');
-    \Drupal::entityManager();
+    $this->assertNotNull(\Drupal::entityManager());
   }
 
   /**
@@ -84,7 +84,7 @@ public function testEntityManager() {
    */
   public function testDatabase() {
     $this->setMockContainerService('database');
-    \Drupal::database();
+    $this->assertNotNull(\Drupal::database());
   }
 
   /**
@@ -92,7 +92,7 @@ public function testDatabase() {
    */
   public function testCache() {
     $this->setMockContainerService('cache.test');
-    \Drupal::cache('test');
+    $this->assertNotNull(\Drupal::cache('test'));
   }
 
   /**
@@ -104,9 +104,11 @@ public function testKeyValueExpirable() {
       ->getMock();
     $keyvalue->expects($this->once())
       ->method('get')
-      ->with('test_collection');
+      ->with('test_collection')
+      ->will($this->returnValue(TRUE));
     $this->setMockContainerService('keyvalue.expirable', $keyvalue);
-    \Drupal::keyValueExpirable('test_collection');
+
+    $this->assertNotNull(\Drupal::keyValueExpirable('test_collection'));
   }
 
   /**
@@ -114,7 +116,7 @@ public function testKeyValueExpirable() {
    */
   public function testLock() {
     $this->setMockContainerService('lock');
-    \Drupal::lock();
+    $this->assertNotNull(\Drupal::lock());
   }
 
   /**
@@ -126,9 +128,11 @@ public function testConfig() {
       ->getMock();
     $config->expects($this->once())
       ->method('get')
-      ->with('test_config');
+      ->with('test_config')
+      ->will($this->returnValue(TRUE));
     $this->setMockContainerService('config.factory', $config);
-    \Drupal::config('test_config');
+
+    $this->assertNotNull(\Drupal::config('test_config'));
   }
 
   /**
@@ -140,9 +144,11 @@ public function testQueue() {
       ->getMock();
     $queue->expects($this->once())
       ->method('get')
-      ->with('test_queue', TRUE);
+      ->with('test_queue', TRUE)
+      ->will($this->returnValue(TRUE));
     $this->setMockContainerService('queue', $queue);
-    \Drupal::queue('test_queue', TRUE);
+
+    $this->assertNotNull(\Drupal::queue('test_queue', TRUE));
   }
 
   /**
@@ -154,9 +160,11 @@ public function testKeyValue() {
       ->getMock();
     $keyvalue->expects($this->once())
       ->method('get')
-      ->with('test_collection');
+      ->with('test_collection')
+      ->will($this->returnValue(TRUE));
     $this->setMockContainerService('keyvalue', $keyvalue);
-    \Drupal::keyValue('test_collection');
+
+    $this->assertNotNull(\Drupal::keyValue('test_collection'));
   }
 
   /**
@@ -164,7 +172,7 @@ public function testKeyValue() {
    */
   public function testState() {
     $this->setMockContainerService('state');
-    \Drupal::state();
+    $this->assertNotNull(\Drupal::state());
   }
 
   /**
@@ -172,7 +180,7 @@ public function testState() {
    */
   public function testHttpClient() {
     $this->setMockContainerService('http_default_client');
-    \Drupal::httpClient();
+    $this->assertNotNull(\Drupal::httpClient());
   }
 
   /**
@@ -184,9 +192,11 @@ public function testEntityQuery() {
       ->getMock();
     $query->expects($this->once())
       ->method('get')
-      ->with('test_entity', 'OR');
+      ->with('test_entity', 'OR')
+      ->will($this->returnValue(TRUE));
     $this->setMockContainerService('entity.query', $query);
-    \Drupal::entityQuery('test_entity', 'OR');
+
+    $this->assertNotNull(\Drupal::entityQuery('test_entity', 'OR'));
   }
 
   /**
@@ -198,9 +208,11 @@ public function testEntityQueryAggregate() {
       ->getMock();
     $query->expects($this->once())
       ->method('getAggregate')
-      ->with('test_entity', 'OR');
+      ->with('test_entity', 'OR')
+      ->will($this->returnValue(TRUE));
     $this->setMockContainerService('entity.query', $query);
-    \Drupal::entityQueryAggregate('test_entity', 'OR');
+
+    $this->assertNotNull(\Drupal::entityQueryAggregate('test_entity', 'OR'));
   }
 
   /**
@@ -208,7 +220,7 @@ public function testEntityQueryAggregate() {
    */
   public function testFlood() {
     $this->setMockContainerService('flood');
-    \Drupal::flood();
+    $this->assertNotNull(\Drupal::flood());
   }
 
   /**
@@ -216,7 +228,7 @@ public function testFlood() {
    */
   public function testModuleHandler() {
     $this->setMockContainerService('module_handler');
-    \Drupal::moduleHandler();
+    $this->assertNotNull(\Drupal::moduleHandler());
   }
 
   /**
@@ -224,7 +236,7 @@ public function testModuleHandler() {
    */
   public function testTypedData() {
     $this->setMockContainerService('typed_data');
-    \Drupal::typedData();
+    $this->assertNotNull(\Drupal::typedData());
   }
 
   /**
@@ -232,7 +244,7 @@ public function testTypedData() {
    */
   public function testToken() {
     $this->setMockContainerService('token');
-    \Drupal::token();
+    $this->assertNotNull(\Drupal::token());
   }
 
   /**
@@ -240,7 +252,7 @@ public function testToken() {
    */
   public function testUrlGenerator() {
     $this->setMockContainerService('url_generator');
-    \Drupal::urlGenerator();
+    $this->assertNotNull(\Drupal::urlGenerator());
   }
 
   /**
@@ -254,9 +266,11 @@ public function testUrl() {
       ->getMock();
     $generator->expects($this->once())
       ->method('generateFromRoute')
-      ->with('test_route', $route_parameters, $options);
+      ->with('test_route', $route_parameters, $options)
+      ->will($this->returnValue(TRUE));
     $this->setMockContainerService('url_generator', $generator);
-    \Drupal::url('test_route', $route_parameters, $options);
+
+    $this->assertNotNull(\Drupal::url('test_route', $route_parameters, $options));
   }
 
   /**
@@ -264,7 +278,7 @@ public function testUrl() {
    */
   public function testLinkGenerator() {
     $this->setMockContainerService('link_generator');
-    \Drupal::linkGenerator();
+    $this->assertNotNull(\Drupal::linkGenerator());
   }
 
   /**
@@ -278,9 +292,11 @@ public function testL() {
       ->getMock();
     $generator->expects($this->once())
       ->method('generate')
-      ->with('Test title', 'test_route', $route_parameters, $options);
+      ->with('Test title', 'test_route', $route_parameters, $options)
+      ->will($this->returnValue(TRUE));
     $this->setMockContainerService('link_generator', $generator);
-    \Drupal::l('Test title', 'test_route', $route_parameters, $options);
+
+    $this->assertNotNull(\Drupal::l('Test title', 'test_route', $route_parameters, $options));
   }
 
   /**
@@ -288,7 +304,7 @@ public function testL() {
    */
   public function testTranslation() {
     $this->setMockContainerService('string_translation');
-    \Drupal::translation();
+    $this->assertNotNull(\Drupal::translation());
   }
 
   /**
@@ -296,7 +312,7 @@ public function testTranslation() {
    */
   public function testLanguageManager() {
     $this->setMockContainerService('language_manager');
-    \Drupal::languageManager();
+    $this->assertNotNull(\Drupal::languageManager());
   }
 
   /**
@@ -304,7 +320,7 @@ public function testLanguageManager() {
    */
   public function testCsrfToken() {
     $this->setMockContainerService('csrf_token');
-    \Drupal::csrfToken();
+    $this->assertNotNull(\Drupal::csrfToken());
   }
 
   /**
@@ -312,7 +328,7 @@ public function testCsrfToken() {
    */
   public function testTransliteration() {
     $this->setMockContainerService('transliteration');
-    \Drupal::transliteration();
+    $this->assertNotNull(\Drupal::transliteration());
   }
 
   /**
@@ -331,6 +347,9 @@ protected function setMockContainerService($service_name, $return = NULL) {
     if (isset($return)) {
       $expects->will($this->returnValue($return));
     }
+    else {
+      $expects->will($this->returnValue(TRUE));
+    }
 
     \Drupal::setContainer($this->container);
   }