private async Task LoadWeatherAsync(IEnumerable <City> cities)
{
var service = new OpenWeatherMapService();
List <WeatherForecast> forecast = new List <WeatherForecast>();
foreach (var cityFollowed in cities)
{
var weather = await service.GetCurrentWeatherByCityAsync(cityFollowed);
forecast.Add(weather);
}
Forecast.ItemsSource = forecast;
}