A true gentleman leaves no puzzle unsolved

[torkell]

Okay, so it turns out that talismancer's post yesterday was filler. The moral balance has swung back!

As tempting as it is to fulfill the entirety of NaBloPoMo with us commenting on each other's posts, I feel like I should actually write something. So in the interests of increasing audience participation, I shall set a Java puzzler.

The puzzler consists of the following class:

import java.util.ArrayList;

public class Foo {
    private ArrayList<Object> barList = new ArrayList<Object>();

    public void fillBarList() {
        for (int i = 0; i < 10; i++) {
            Object o = new Object();
            System.out.println("Adding " + o + " at index " + i);
            barList.add(o);
        }
    }

    public void emptyBarList() {
        for (Object o : barList) {
            System.out.println("Removing " + o);
            barList.remove(o);
        }
    }

    public static void main(String[] args) {
        Foo f = new Foo();
        f.fillBarList();
        f.emptyBarList();
    }
}

Without running it (because that would be cheating and you will be mocked for it), what do you think will happen when Foo.main() is called?