Assert\Assertion::notIsInstanceOf PHP Method

    public static function notIsInstanceOf($value, $className, $message = null, $propertyPath = null)
    {
        if ($value instanceof $className) {
            $message = sprintf($message ?: 'Class "%s" was not expected to be instanceof of "%s".', static::stringify($value), $className);
            throw static::createException($value, $message, static::INVALID_NOT_INSTANCE_OF, $propertyPath, array('class' => $className));
        }
        return true;
    }

 public function testValidNotIsInstanceOf()
 {
     Assertion::notIsInstanceOf(new \stdClass(), 'PDO');
 }