private function validateGeneralConfigurationSectionInExtra(array $extra)
    {
        if (!isset($extra['phplist/core'])) {
            return;
        }
        $this->validatePhpListSectionInExtra($extra);

        if (!isset($extra['phplist/core']['configuration'])) {
            return;
        }
        if (!is_array($extra['phplist/core']['configuration'])) {
            throw new \InvalidArgumentException(
                'The extras.phplist/core.configuration section in the composer.json must be an array.',
                1508165934
            );
        }
    }