private void UpdateSpecialResources() {
XYield totalSpecial = new XYield();
var specialResources = Composition.GetPlanetData().Select(pd => pd.SpecialResources);
if (!specialResources.IsNullOrEmpty()) {
var totalSpecialFromPlanets = specialResources.Aggregate<XYield>(
(accumulator, x) => new XYield() { // Aggregate throws up if source enumerable is empty
Special_1 = accumulator.Special_1 + x.Special_1,
Special_2 = accumulator.Special_2 + x.Special_2,
Special_3 = accumulator.Special_3 + x.Special_3
});
totalSpecial.Add(totalSpecialFromPlanets);
}
totalSpecial.Add(Composition.StarData.SpecialResources);
SpecialResources = totalSpecial;
}