public MainViewModel()
{
InstanceConverter = new InstanceInSetToStringConverter();
LocationCollection = new ObservableCollectionContentNotifying <DemandLocation>();
ChartData = new ObservableCollectionContentNotifying <PlotTrend>();
LocationCollection.ClearAndAddRange(Selects.GetDemandLocations().Take(5));
var locs = new List <int> {
18, 55
};
locs.ForEach(x => LocationCollection.Single(y => y.LocationID == x).IsUsed = true);
UpdateHeader();
SelectedItem = TrendChoices.FiscalPeriod;
UpdateChartData();
LocationCollection.OnCollectionItemChanged += UpdateHeader;
}