protected function collectDevServiceProviders($configKey)
    {
        // Get the Config key where devProviders are located.
        $devProvidersConfigLocation = Config::get($configKey);

        // Get Providers keys.
        $keys = is_string($devProvidersConfigLocation) ? [$devProvidersConfigLocation] : $devProvidersConfigLocation;

        // Return Dev Providers.
        return collect($keys)->transform(function ($location) {
            // Transform each Location key to the actual array
            // containing the Providers.
            return Config::get($location);
        })->reject(function ($arrayOfProviders) {
            // Remove all null values
            return is_null($arrayOfProviders);
        })->flatten()->unique()->values();
    }