TreeSet метод first() java

Подскажите как можно реализовать метод который должен возвращать самый малый элемент

public class TreeLinkedSet<T extends Comparable<T>> implements Iterable<T> {
    @Override
    public Iterator<T> iterator() {
        return new Iterator<T>() {
            private Container cursor;
            {
                if (root != null) {
                    cursor = passLeft(root);
                }
            }
            @Override
            public boolean hasNext() {
                return cursor != null;
            }
            @Override
            public T next() {
                T res = cursor.val;
                if (cursor.right != null) {
                    cursor = passLeft(cursor.right);
                } else if (cursor.right == null) {
                    cursor = passBack(cursor);
                }
                return res;
            }
        };
    }
    private class Container implements Comparable<Container> {
        private Container left;
        private Container right;
        private Container prior;
        private T val;
        public Container(T val) {
            this.val = val;
        }
        @Override
        public int compareTo(Container o) {
            return val.compareTo(o.val);
        }
    }
    private Container root;
    private int size;
    public int Size() {
        return size;
    }
    public void add(T t) {
        Container c = new Container(t);
        if (root == null) {
            root = c;
            size++;
        } else {
            choose(root, c);
        }
    }
    private void choose(Container base, Container c) {
        if (c.compareTo(base) < 0) {
            if (base.left == null) {
                base.left = c;
                c.prior = base;
                size++;
            } else {
                choose(base.left, c);
            }
        }
        if (c.compareTo(base) > 0) {
            if (base.right == null) {
                base.right = c;
                c.prior = base;
                size++;
            } else {
                choose(base.right, c);
            }
        }
    }
    private Container passLeft(Container c) {
        return c.left == null ? c : passLeft(c.left);
    }
    private Container passBack(Container c) {
        if (c.prior != null) {
            return c.prior.compareTo(c) > 0 ? c.prior : passBack(c.prior);
        }
        return null;
    }
    public T[] toArray(T[] type) {
        T[] res = (T[]) Array.newInstance(type.getClass().getComponentType(), size);
        int i = 0;
        for (T t : this) {
            res[i++] = t;
        }
        return res;
    }