ProviderExtensions: Added check if gearbox is null, reformated and commented switch statement

VectoCore/VectoCore/Utils/ProviderExtensions.cs

@@ -110,21 +110,33 @@ namespace TUGraz.VectoCore.Utils
 			return next;
 		}
 
-		public static IPowerTrainComponent AddComponent(this IPowerTrainComponent prev, IGearbox gearbox, RetarderData data,
-			IVehicleContainer container)
+		public static IPowerTrainComponent AddComponent(this IPowerTrainComponent prev, IGearbox gearbox,
+			RetarderData data, IVehicleContainer container)
 		{
+			if (gearbox is null) {
+				return prev;
+			}
+
 			switch (data.Type) {
 				case RetarderType.TransmissionOutputRetarder:
+					// --> Transmission Output Retarder --> Gearbox -->
 					return prev.AddComponent(new Retarder(container, data.LossMap, data.Ratio)).AddComponent(gearbox);
+
 				case RetarderType.TransmissionInputRetarder:
+					// --> Gearbox --> Transmission Input Retarder -->
 					return prev.AddComponent(gearbox).AddComponent(new Retarder(container, data.LossMap, data.Ratio));
+
 				case RetarderType.None:
 				case RetarderType.LossesIncludedInTransmission:
 				case RetarderType.EngineRetarder:
+					// --> DummyRetarder --> Gearbox -->
 					return prev.AddComponent(new DummyRetarder(container)).AddComponent(gearbox);
+
+				case RetarderType.AxlegearInputRetarder:
+					//todo mk2022-03-21 implement this!
+					throw new NotImplementedException();
+
 				default:
-					// ReSharper disable once NotResolvedInText
-					// ReSharper disable once LocalizableElement
 					throw new ArgumentOutOfRangeException("retarderdata.Type", data.Type.ToString(), "Retardertype unknown");
 			}
 		}