getPlateHandler function
Gives plate handler based on normalized form of the plate
Implementation
PlateHandler getPlateHandler(NormalizedPlate plate) {
if (plate.numbers.length == 7) {
return carHandler;
} else if (plate.numbers.length == 8) {
return motorcycleHandler;
} else {
throw Exception('Plate number should 8 or 7');
}
}