public async Task <List <RootObject> > GetHistoricalWeatherAsync(string location, DateTime startDate, int duration)
{
var dateOneYearAgo = startDate.AddYears(-1);
var oneYearAgo = await _weatherClient.GetHistoricalWeatherDataAsync(location, dateOneYearAgo, duration);
var dateTwoYearsAgo = startDate.AddYears(-2);
var twoYearsAgo = await _weatherClient.GetHistoricalWeatherDataAsync(location, dateTwoYearsAgo, duration);
var dateThreeYearsAgo = startDate.AddYears(-3);
var threeYearsAgo = await _weatherClient.GetHistoricalWeatherDataAsync(location, dateThreeYearsAgo, duration);
List <RootObject> items = new List <RootObject>
{
oneYearAgo,
twoYearsAgo,
threeYearsAgo
};
return(items);
}