Add missing return types

Author: wouterj

Constraints/IsbnValidator.php

@@ -175,6 +175,9 @@ protected function validateIsbn13(string $isbn)
         return 0 === $checkSum % 10 ? true : Isbn::CHECKSUM_FAILED_ERROR;
     }
 
+    /**
+     * @return string
+     */
     protected function getMessage(Isbn $constraint, string $type = null)
     {
         if (null !== $constraint->message) {

Exception/ValidationFailedException.php

@@ -28,6 +28,9 @@ public function __construct(mixed $value, ConstraintViolationListInterface $viol
         parent::__construct($violations);
     }
 
+    /**
+     * @return mixed
+     */
     public function getValue()
     {
         return $this->value;