private static function forkCallMapClass(\ReflectionFunction $function): \ReflectionClass
    {
        try {
            $compile = self::$compile;
            $compile(self::createProxyCode($function));
        } catch (\ParseError $pe) {
            throw new ProxyCreationFailure(
                    'Failure while creating callable CallMap instance of '
                    . $function->getName() . '(): ' . $pe->getMessage(),
                    $pe
            );
        }

        return new \ReflectionClass($function->getName() . 'CallMapProxy');
    }