diff --git a/core/tests/Drupal/Tests/Component/Utility/HtmlTest.php b/core/tests/Drupal/Tests/Component/Utility/HtmlTest.php
index 6e15893..5d91526 100644
--- a/core/tests/Drupal/Tests/Component/Utility/HtmlTest.php
+++ b/core/tests/Drupal/Tests/Component/Utility/HtmlTest.php
@@ -33,7 +33,7 @@ class HtmlTest extends UnitTestCase {
   public function testLoad($html, $tags) {
     $doc = Html::load($html);
     // If we have a document we did our job.
-    $this->assertTrue(is_a($doc, '\DOMDocument'));
+    $this->assertInstanceOf('\DomDocument', $doc);
 
     foreach ($tags as $tag_name => $length) {
       $tag = $doc->getElementsByTagName($tag_name);
diff --git a/core/tests/Drupal/Tests/Component/Utility/UserAgentTest.php b/core/tests/Drupal/Tests/Component/Utility/UserAgentTest.php
index 3256587..b14c347 100644
--- a/core/tests/Drupal/Tests/Component/Utility/UserAgentTest.php
+++ b/core/tests/Drupal/Tests/Component/Utility/UserAgentTest.php
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Container Drupal\Tests\Component\Utility\UserAgentTest
+ * Container Drupal\Tests\Component\Utility\UserAgentTest.
  */
 
 namespace Drupal\Tests\Component\Utility;
@@ -76,9 +76,16 @@ protected function getMappings() {
    */
   public function testGetBestMatchingLangcode($accept_language, $expected) {
     $result = UserAgent::getBestMatchingLangcode($accept_language, $this->getLanguages(), $this->getMappings());
-    $this->assertSame($expected, $result, $accept_language);
+    $this->assertSame($expected, $result);
   }
 
+  /**
+   * Data provider for testGetBestMatchingLangcode().
+   *
+   * @return array
+   *   - An accept-language string.
+   *   - Expected best matching language code.
+   */
   public function providerTestGetBestMatchingLangcode() {
     return array(
       // Equal qvalue for each language, choose the site preferred one.
@@ -146,9 +153,9 @@ public function providerTestGetBestMatchingLangcode() {
       array('zh-tw, en-us;q=0.90, en;q=0.80, zh;q=0.70', 'zh-hant'),
       array('zh-hant, en-us;q=0.90, en;q=0.80, zh;q=0.70', 'zh-hant'),
       array('zh-hans, en-us;q=0.90, en;q=0.80, zh;q=0.70', 'zh-hans'),
-      // TODO This is copied from RFC4647 but our regex skips the numbers so they
-      // where removed. Our code should be updated so private1-private2 is valid.
-      // http://tools.ietf.org/html/rfc4647#section-3.4
+      // @todo: This is copied from RFC4647 but our regex skips the numbers so
+      // they where removed. Our code should be updated so private1-private2 is
+      // valid. http://tools.ietf.org/html/rfc4647#section-3.4
       array('zh-hant-CN-x-private-private, en-us;q=0.90, en;q=0.80, zh;q=0.70', 'zh-hant'),
       array('zh-cn', 'zh-hans'),
       array('zh-sg', 'zh-hans'),
@@ -160,6 +167,6 @@ public function providerTestGetBestMatchingLangcode() {
       array('zh-chs', 'zh-hans'),
       array('zh-cht', 'zh-hant'),
     );
-
   }
+
 }