Improve unique value constraint handling

Author: peldax

composer.lock

@@ -126,6 +126,8 @@ private static function recursiveValidate(array $rawValue, \stdClass $options) :
                 if (\array_key_exists($innerValue, $differentValues)) {
                     throw new UniqueConstraintNotSatisfied();
                 }
+
+                $differentValues[$innerValue] = true;
             }
         }