Update to Drupal 8.1.5. For more information, see https://www.drupal.org/project/drupal/releases/8.1.5

core/lib/Drupal/Core/Render/Element/Checkboxes.php

@@ -17,7 +17,7 @@ use Drupal\Core\Form\FormStateInterface;
  * @code
  * $form['high_school']['tests_taken'] = array(
  *   '#type' => 'checkboxes',
- *   '#options' => array('SAT' => $this->t('SAT'), 'ACT' => $this->t('ACT'))),
+ *   '#options' => array('SAT' => $this->t('SAT'), 'ACT' => $this->t('ACT')),
  *   '#title' => $this->t('What standardized tests did you take?'),
  *   ...
  * );

core/lib/Drupal/Core/Render/Element/StatusMessages.php

@@ -12,7 +12,7 @@ namespace Drupal\Core\Render\Element;
  * $build['status_messages'] = [
  *   '#type' => 'status_messages',
  * ];
- * @end
+ * @endcode
  *
  * @RenderElement("status_messages")
  */

core/lib/Drupal/Core/Render/RenderCacheInterface.php

@@ -64,7 +64,7 @@ interface RenderCacheInterface {
    *   this array.
    *
    * @return bool|null
-   *  Returns FALSE if no cache item could be created, NULL otherwise.
+   *   Returns FALSE if no cache item could be created, NULL otherwise.
    *
    * @see ::get()
    */