public function findGeneralConfiguration(): array
    {
        /** @var array[] $configurationSets */
        $configurationSets = [[]];

        $modules = $this->packageRepository->findModules();
        foreach ($modules as $module) {
            $extra = $module->getExtra();
            $this->validateGeneralConfigurationSectionInExtra($extra);
            if (!isset($extra['phplist/core']['configuration'])) {
                continue;
            }

            $configurationSets[] = $extra['phplist/core']['configuration'];
        }

        return /** @scrutinizer ignore-call */ array_replace_recursive(...$configurationSets);
    }