diff --git a/core/modules/filter/filter.module b/core/modules/filter/filter.module
index bbbd774..b55066f 100644
--- a/core/modules/filter/filter.module
+++ b/core/modules/filter/filter.module
@@ -4,6 +4,7 @@
  * @file
  * Framework for handling the filtering of content.
  */
+
 use Drupal\Core\Cache\CacheBackendInterface;
 use Drupal\Core\Template\Attribute;
 
@@ -574,6 +575,7 @@ function filter_default_format($account = NULL) {
  *
  * @param string $format_id
  *   A text format ID.
+ *
  * @return array
  *   All filter types used by filters of a given text format.
  *
@@ -812,9 +814,9 @@ function filter_list_format($format_id) {
  *   The caller may set this to FALSE when the output is already cached
  *   elsewhere to avoid duplicate cache lookups and storage.
  * @param array $filter_types_to_skip
- *   An array of filter types to skip, or the empty array (default) to skip no
- *   filter types. All of the format's filters will be applied, except for
- *   filters of the types that are marked to be skipped.
+ *   (optional) An array of filter types to skip, or an empty array (default)
+ *   to skip no filter types. All of the format's filters will be applied,
+ *   except for filters of the types that are marked to be skipped.
  *   FILTER_TYPE_HTML_RESTRICTOR is the only type that cannot be skipped.
  *
  * @return
diff --git a/core/modules/filter/lib/Drupal/filter/Tests/FilterAPITest.php b/core/modules/filter/lib/Drupal/filter/Tests/FilterAPITest.php
index d98e5a8..e355f2d 100644
--- a/core/modules/filter/lib/Drupal/filter/Tests/FilterAPITest.php
+++ b/core/modules/filter/lib/Drupal/filter/Tests/FilterAPITest.php
@@ -13,6 +13,7 @@
  * Tests the behavior of Filter's API.
  */
 class FilterAPITest extends WebTestBase {
+
   public static function getInfo() {
     return array(
       'name' => 'API',
@@ -70,12 +71,12 @@ function testCheckMarkup() {
     $this->assertIdentical(
       check_markup($text, 'filtered_html', '', FALSE, array()),
       $expected_filtered_text,
-      t('Expected filter result.')
+      'Expected filter result.'
     );
     $this->assertIdentical(
       check_markup($text, 'filtered_html', '', FALSE, array(FILTER_TYPE_MARKUP_LANGUAGE)),
       $expected_filter_text_without_html_generators,
-      t('Expected filter result when skipping FILTER_TYPE_MARKUP_LANGUAGE filters.')
+      'Expected filter result when skipping FILTER_TYPE_MARKUP_LANGUAGE filters.'
     );
     // Related to @see FilterSecurityTest.php/testSkipSecurityFilters(), but
     // this check focuses on the ability to filter multiple filter types at once.
@@ -84,23 +85,27 @@ function testCheckMarkup() {
     $this->assertIdentical(
       check_markup($text, 'filtered_html', '', FALSE, array(FILTER_TYPE_HTML_RESTRICTOR, FILTER_TYPE_MARKUP_LANGUAGE)),
       $expected_filter_text_without_html_generators,
-      t('Expected filter result when skipping FILTER_TYPE_MARKUP_LANGUAGE filters, even when trying to disable filters of the FILTER_TYPE_HTML_RESTRICTOR type.')
+      'Expected filter result when skipping FILTER_TYPE_MARKUP_LANGUAGE filters, even when trying to disable filters of the FILTER_TYPE_HTML_RESTRICTOR type.'
     );
   }
 
+  /**
+   * Tests the function filter_get_filter_types_by_format().
+   */
   function testFilterFormatAPI() {
     // Test on filtered_html.
     $this->assertEqual(
       filter_get_filter_types_by_format('filtered_html'),
       array(FILTER_TYPE_HTML_RESTRICTOR, FILTER_TYPE_MARKUP_LANGUAGE),
-      t('filter_get_filter_types_by_format() works as expected for the filtered_html format.')
+      'filter_get_filter_types_by_format() works as expected for the filtered_html format.'
     );
 
     // Test on full_html.
     $this->assertEqual(
       filter_get_filter_types_by_format('full_html'),
       array(FILTER_TYPE_HTML_RESTRICTOR),
-      t('filter_get_filter_types_by_format() works as expected for the full_html format.')
+      'filter_get_filter_types_by_format() works as expected for the full_html format.'
     );
   }
+
 }
diff --git a/core/modules/filter/lib/Drupal/filter/Tests/FilterSecurityTest.php b/core/modules/filter/lib/Drupal/filter/Tests/FilterSecurityTest.php
index 1e37b95..006bfe3 100644
--- a/core/modules/filter/lib/Drupal/filter/Tests/FilterSecurityTest.php
+++ b/core/modules/filter/lib/Drupal/filter/Tests/FilterSecurityTest.php
@@ -90,13 +90,12 @@ function testDisableFilterModule() {
   }
 
   /**
-   * Tests that when security filters are marked to be skipped, they are still
-   * enforced anyway.
+   * Tests that security filters are enforced even when marked to be skipped.
    */
   function testSkipSecurityFilters() {
     $text = "Text with some disallowed tags: <script />, <em><object>unicorn</object></em>, <i><table></i>.";
     $expected_filtered_text = "Text with some disallowed tags: , <em>unicorn</em>, .";
-    $this->assertEqual(check_markup($text, 'filtered_html', '', FALSE, array()), $expected_filtered_text, t('Expected filter result.'));
-    $this->assertEqual(check_markup($text, 'filtered_html', '', FALSE, array(FILTER_TYPE_HTML_RESTRICTOR)), $expected_filtered_text, t('Expected filter result, even when trying to disable filters of the FILTER_TYPE_HTML_RESTRICTOR type.'));
+    $this->assertEqual(check_markup($text, 'filtered_html', '', FALSE, array()), $expected_filtered_text, 'Expected filter result.');
+    $this->assertEqual(check_markup($text, 'filtered_html', '', FALSE, array(FILTER_TYPE_HTML_RESTRICTOR)), $expected_filtered_text, 'Expected filter result, even when trying to disable filters of the FILTER_TYPE_HTML_RESTRICTOR type.');
   }
 }