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

core/lib/Drupal/Core/Lock/LockBackendAbstract.php

@@ -71,4 +71,5 @@ abstract class LockBackendAbstract implements LockBackendInterface {
     }
     return $this->lockId;
   }
+
 }

core/lib/Drupal/Core/Lock/LockBackendInterface.php

@@ -68,8 +68,8 @@ interface LockBackendInterface {
    *
    * @param string $name
    *   Lock name. Limit of name's length is 255 characters.
-   * @param float $timeout = 30.0
-   *   (optional) Lock lifetime in seconds.
+   * @param float $timeout
+   *   (optional) Lock lifetime in seconds. Defaults to 30.0.
    *
    * @return bool
    */
@@ -95,8 +95,8 @@ interface LockBackendInterface {
    *
    * @param string $name
    *   Lock name currently being locked.
-   * @param int $delay = 30
-   *   Milliseconds to wait for.
+   * @param int $delay
+   *   Milliseconds to wait for. Defaults to 30.
    *
    * @return bool
    *   TRUE if the lock holds, FALSE if it may be available. You still need to
@@ -128,4 +128,5 @@ interface LockBackendInterface {
    * @return string
    */
   public function getLockId();
+
 }

core/lib/Drupal/Core/Lock/NullLockBackend.php

@@ -57,4 +57,5 @@ class NullLockBackend implements LockBackendInterface {
     }
     return $this->lockId;
   }
+
 }

core/lib/Drupal/Core/Lock/PersistentDatabaseLockBackend.php

@@ -28,4 +28,5 @@ class PersistentDatabaseLockBackend extends DatabaseLockBackend {
     // @see \Drupal\Core\Lock\LockBackendInterface::getLockId()
     $this->lockId = 'persistent';
   }
+
 }