diff -u b/core/tests/Drupal/Tests/Component/Utility/Stub/StubUnicode.php b/core/tests/Drupal/Tests/Component/Utility/Stub/StubUnicode.php
--- b/core/tests/Drupal/Tests/Component/Utility/Stub/StubUnicode.php
+++ b/core/tests/Drupal/Tests/Component/Utility/Stub/StubUnicode.php
@@ -4,6 +4,7 @@
  * @file
  * Contains \Drupal\Tests\Component\Utility\Stub\StubUnicode
  */
+
 namespace Drupal\Tests\Component\Utility\Stub;
 
 use Drupal\Component\Utility\Unicode;
@@ -13,7 +14,6 @@
  *
  * @see \Drupal\Tests\Component\Utility\Unicode
  */
-
 class StubUnicode extends Unicode {
 
   /**
@@ -61,6 +61,9 @@
     }
   }
 
+  /**
+   * {@inheritdoc}
+   */
   public static function getPhpVersion() {
     return static::$currentPhpVersion;
   }
diff -u b/core/tests/Drupal/Tests/Component/Utility/UnicodeTest.php b/core/tests/Drupal/Tests/Component/Utility/UnicodeTest.php
--- b/core/tests/Drupal/Tests/Component/Utility/UnicodeTest.php
+++ b/core/tests/Drupal/Tests/Component/Utility/UnicodeTest.php
@@ -46,15 +46,17 @@
    * @covers ::check
    */
   public function testCheck($fake_php_version, $variable_name, $new_value, $passes_check) {
-
-    // Save the current variable into a property so we can access it
-    // in StubUnicode::iniGet().
+    // Save the current variable into a property so we can access it in
+    // StubUnicode::iniGet().
     StubUnicode::$currentIniVariable = array(
       'variable_name' => $variable_name,
       'variable_value' => $new_value,
     );
+    // Save the current PHP version into a property so we can access it in
+    // StubUnicode::getPhpVersion().
     StubUnicode::$currentPhpVersion = $fake_php_version;
 
+    // Run the stub method to find out what it returns.
     $check = StubUnicode::check();
 
     if ($passes_check) {
@@ -66,10 +68,8 @@
       // not successful.
       $this->assertEquals($check, $variable_name);
     }
-
   }
 
-
   /**
    * Data provider for testCheck().
    *