Update to Drupal 8.1.2. For more information, see https://www.drupal.org/project/drupal/releases/8.1.2

core/lib/Drupal/Core/Field/ChangedFieldItemList.php

@@ -17,4 +17,5 @@ class ChangedFieldItemList extends FieldItemList {
     // It is not possible to edit the changed field.
     return AccessResult::allowedIf($operation !== 'edit');
   }
+
 }

core/lib/Drupal/Core/Field/FieldItemInterface.php

@@ -98,7 +98,7 @@ interface FieldItemInterface extends ComplexDataInterface {
   /**
    * Gets the langcode of the field values held in the object.
    *
-   * @return $langcode
+   * @return string
    *   The langcode.
    */
   public function getLangcode();

core/lib/Drupal/Core/Field/FieldItemListInterface.php

@@ -44,7 +44,7 @@ interface FieldItemListInterface extends ListInterface, AccessibleInterface {
   /**
    * Gets the langcode of the field values held in the object.
    *
-   * @return $langcode
+   * @return string
    *   The langcode.
    */
   public function getLangcode();
@@ -181,7 +181,7 @@ interface FieldItemListInterface extends ListInterface, AccessibleInterface {
    */
   public function view($display_options = array());
 
-  /*
+  /**
    * Populates a specified number of field items with valid sample data.
    *
    * @param int $count

core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/EntityReferenceIdFormatter.php

@@ -40,4 +40,5 @@ class EntityReferenceIdFormatter extends EntityReferenceFormatterBase {
 
     return $elements;
   }
+
 }

core/lib/Drupal/Core/Field/Plugin/Field/FieldType/BooleanItem.php

@@ -119,4 +119,5 @@ class BooleanItem extends FieldItemBase implements OptionsProviderInterface {
     $values['value'] = mt_rand(0, 1);
     return $values;
   }
+
 }