Error in example app

[mvantuch]

In Boa/Modules/WeatherDetail/WeatherPageViewController.swift,
there's an error in the code snippet on line number 109:

extension WeatherPageViewController {
    fileprivate func initViewControllers() {
        let weatherDetailStoryboard = UIStoryboard(name: "WeatherDetail", bundle: nil)
        
        orderedWeatherDetailViewControllers = weatherReports.map {
            let weatherDetailVC = weatherDetailStoryboard.instantiateViewController(withIdentifier: "WeatherDetail") as! WeatherDetailViewController
            weatherDetailVC.weatherReport = $0
            weatherDetailVC.styler = styler
            return weatherDetailVC
        }
    }
}

There should be used ? or ! in order to apply correct method, which returns [T] instead of just returning optional type U? for example. I think it is a result of compiler changes explained here:
https://swift.org/blog/iuo/