java merge iterators

import java.util.*;

public class MergeIterator implements Iterator<Integer> {

    private List<Iterator<Integer>> iterators;
    private List<Integer> values;

    public MergeIterator (List<Iterator<Integer>> iterators) {
        this.iterators = iterators;
        this.values = new ArrayList<>();
    }

    @Override
    public boolean hasNext() {
        return false;
    }

    @Override
    public Integer next() {
        return foo();
    }

    private Integer foo(){
        if(values.size() == 0){
            for(Iterator<Integer> i : iterators){
                if(i.hasNext()){
                    values.add(i.next());
                }
            }

            Collections.sort(values);
        }
        Integer result = values.get(0);
        values.remove(result);
        return result;
    }
}