diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index a838eef..8d509ae 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -1714,7 +1714,8 @@ function theme_links($variables) {
         }
         else {
           // @todo theme_links() should *really* use the same parameters as l(),
-          // and just take an array of '#type' => 'link' elements.
+          //   and just take an array of '#type' => 'link' elements, see
+          //   https://drupal.org/node/2102777.
           // Pass in $link as $options, as they share the same keys.
           if (isset($link['href'])) {
             $item = l($link['title'], $link['href'], $link);
diff --git a/core/modules/block/block.module b/core/modules/block/block.module
index 319867c..d0b35b7 100644
--- a/core/modules/block/block.module
+++ b/core/modules/block/block.module
@@ -124,7 +124,6 @@ function block_menu() {
   );
   // Block administration is tied to the theme and plugin definition so
   // that the plugin can appropriately attach to this URL structure.
-  // that the plugin can appropriately attach to this URL structure.
   // @todo D8: Use dynamic % arguments instead of static, hard-coded theme names
   //   and plugin IDs to decouple the routes from these dependencies and allow
   //   hook_menu_local_tasks() to check for the untranslated tab_parent path.
diff --git a/core/modules/content_translation/content_translation.contextual_links.yml b/core/modules/content_translation/content_translation.contextual_links.yml
index d869667..25446a8 100644
--- a/core/modules/content_translation/content_translation.contextual_links.yml
+++ b/core/modules/content_translation/content_translation.contextual_links.yml
@@ -1,4 +1,3 @@
 content_translation.contextual_links:
   derivative: 'Drupal\content_translation\Plugin\Derivative\ContentTranslationContextualLinks'
-  class: 'Drupal\content_translation\Plugin\Menu\ContextualLink\ContentTranslationContextualLinks'
   weight: 100
diff --git a/core/modules/content_translation/lib/Drupal/content_translation/Plugin/Derivative/ContentTranslationContextualLinks.php b/core/modules/content_translation/lib/Drupal/content_translation/Plugin/Derivative/ContentTranslationContextualLinks.php
index b5d2193..c6cc8ea 100644
--- a/core/modules/content_translation/lib/Drupal/content_translation/Plugin/Derivative/ContentTranslationContextualLinks.php
+++ b/core/modules/content_translation/lib/Drupal/content_translation/Plugin/Derivative/ContentTranslationContextualLinks.php
@@ -18,7 +18,7 @@
  *
  * @see \Drupal\content_translation\Plugin\Menu\ContextualLink\ContentTranslationContextualLinks
  */
-class ContentTranslationContextualLinks  extends DerivativeBase implements ContainerDerivativeInterface {
+class ContentTranslationContextualLinks extends DerivativeBase implements ContainerDerivativeInterface {
 
   /**
    * The entity manager.
diff --git a/core/modules/contextual/contextual.module b/core/modules/contextual/contextual.module
index c196e5a..3539119 100644
--- a/core/modules/contextual/contextual.module
+++ b/core/modules/contextual/contextual.module
@@ -288,6 +288,7 @@ function contextual_pre_render_links($element) {
   // Transform contextual links into parameters suitable for theme_links().
   $links = array();
   foreach ($items as $class => $item) {
+
     $class = drupal_html_class($class);
     $links[$class] = array(
       'title' => $item['title'],
diff --git a/core/modules/system/system.api.php b/core/modules/system/system.api.php
index de15545..47a5521 100644
--- a/core/modules/system/system.api.php
+++ b/core/modules/system/system.api.php
@@ -879,7 +879,7 @@ function hook_contextual_links_alter(array &$links, $group, array $route_paramet
 }
 
 /**
- * Alters the plugin definition of contextual links.
+ * Alter the plugin definition of contextual links.
  *
  * @param array $contextual_links
  *   An array of contextual_links plugin definitions, keyed by contextual link