impl Lawnmower {
    fn find_home_station(&self) -> Option<&Station> {
        self.neighbouring_stations().iter().find(|station| {
            self.is_suitable_home(station)
        })
    }

    fn is_suitable_home(&self, station: &Station) -> bool {
        station.id == self.home_station_id
            && !station.occupied
            && station.color == StationColor::Red
    }
}
