Method containsKey

lab08/src/hashmap/ULLMap.java:62–67

Returns true if and only if this dictionary contains KEY as the key of some key-value pair.

(K key)

     * key of some key-value pair.
     */
    public boolean containsKey(K key) {
        if (list == null) {
            return false;
        }
        return list.get(key) != null;
    }

    @Override
    public Iterator<K> iterator() {