Method add

src/org/apache/pig/impl/util/IdentityHashSet.java:28–35

(E element)

    IdentityHashMap<E, Object> map = new IdentityHashMap<E, Object>();

    public boolean add(E element) {
        if (map.containsKey(element)) {
            return false;
        } else {
            map.put(element, null);
            return true;
        }
    }

    public boolean addAll(Collection<? extends E> elements) {
        boolean anyChanges = false;