public class Car extends Vehicle
{
   // This instance variable is added to the subclass
   private String licensePlateNumber;
   
   public Car()
   {
      // Use the public interface to access the instance variable of the superclass
      setNumberOfTires(4); // same as this.setNumberOfTires(4)
      licensePlateNumber = "??????";
   }

   // This method is added to the subclass
   public void setLicensePlateNumber(String newValue)
   {
      licensePlateNumber = newValue;
   }

   // This method overrides a method from the superclass
   public String getDescription() 
   {
      return "A car with license plate " + licensePlateNumber;
   }

   // This class inherits the getNumberOfTires and setNumberOfTires methods
}