protected function registerClassMap(array $classMap)
    {
        foreach ($classMap as $file) {
            $arrClasses = require $file;
            if (!ArrayUtils::isHashTable($arrClasses, true)) {
                throw new Exception\RuntimeException('Config autoload for classmap is invalid');
            }

            if (!empty($arrClasses)) {
                $this->loader->registerClasses($arrClasses);
            }
        }
    }