public function getModulesConfig()
    {
        $result = [];
        foreach ($this->modules as $moduleName => $moduleConfig) {
            $className = $moduleConfig['className'];
            $module    = new $className;
            if (!$module instanceof AbstractModule) {
                $errMsg = sprintf('Class "%s" must be extended from %s', $className, AbstractModule::class);
                throw new Exception\RuntimeException($errMsg);
            }
            $config = $module->getConfig();
            $result = ArrayUtils::merge($result, $this->filterModuleConfig($config, $moduleName));
        }
        return $result;
    }