public static function validateHookConfig(array $json) : void
    {
        if (!self::keysExist(['enabled', 'actions'], $json)) {
            throw new \RuntimeException('Config error: invalid hook configuration');
        }
        if (!is_array($json['actions'])) {
            throw new \RuntimeException('Config error: \'actions\' must be an array');
        }
        self::validateActionsConfig($json['actions']);
    }