class WeatherMap {
    let city = "Moscow"
}

class WeatherService {
    //the value is created on first access
    lazy var map = WeatherService.load()

    static func load() -> WeatherMap {
        print("2. Creating WeatherMap")
        return WeatherMap()
    }
}

//a global variable is lazy by itself,
//so "lazy" is not allowed on it
let service = WeatherService()

print("1. Before accessing the map")
print("3. Got the map for", service.map.city)
print("4. Got it again for", service.map.city)
//WeatherMap is created only once