OptionalTest.java

package th.co.geniustree.demo;

import org.junit.Test;

public class OptionalTest {
    @Test
    public void no_optional() {
        Home home = findHomeFromSomeWhere();
        //print cc. of a car in my home
        if (home != null) {
            Car car = home.getCar();
            if (car != null) {
                Engine engine = car.getEngine();
                if (engine != null) {
                    Piston piston = engine.getPiston();
                    System.out.println(piston.getCapacity());
                }
            }
        }
    }

    private Home findHomeFromSomeWhere() {
        return new Home();
    }
}