public class Car
{
    private String name; // For debugging purposes

    private Driver driver;

    public Car(String aName)
    {
        name = aName;
    }

    public Driver getDriver()
    {
        return driver;
    }

    public String getName()
    {
        return name;
    }

    public void setDriver(Driver aDriver)
    {
        Driver oldDriver = driver;

        driver = aDriver;
        if (oldDriver != null && oldDriver.getCar() == this)
        {
            oldDriver.setCar(null);
        }

        if (aDriver != null && aDriver.getCar() != this)
        {
            aDriver.setCar(this);
        }
    }

    // For debugging purposes
    public void print()
    {
        System.out.print("Car's name is " + name);
        if (driver == null)
        {
            System.out.println(" and has no driver");
        }
        else
        {
            System.out.println(" and has driver " + driver.getName());
        }
    }
}