Develop code to define behaviors of an object through methods written in a class using object references and determine the result of calling these methods.

Consider the following code segment:

public class NumberList {
    private ArrayList<Integer> numbers;
    
    public NumberList() {
        numbers = new ArrayList<Integer>();
    }
    
    public void addNumber(int n) {
        numbers.add(n);
    }
    
    public ArrayList<Integer> getNumbers() {
        return numbers;
    }
}

public static void modifyList(ArrayList<Integer> list) {
    list.add(100);
    list = new ArrayList<Integer>();
    list.add(200);
}

public static void main(String[] args) {
    NumberList nl = new NumberList();
    nl.addNumber(10);
    nl.addNumber(20);
    modifyList(nl.getNumbers());
    System.out.println(nl.getNumbers().size());
}

What is printed as a result of executing this code?