image/svg+xml
WheeledVehicle
Car
Bicycle
Motorbike
Bike
ride( ride()
MotoredVehicle engine_start()fuel_level()
? ? ? ?
int fuel_level() { return fuel_lev;}
MotoredVehicle engine_start()fuel_level()
int fuel_level() { return fuel_lev;}
int fuel_level() { return fuel_lev;}
Code duplication !