The interface of Iterator contains next(), hasNext(), and remoce().

Assume the following: The Iterator interface is as discussed in lecture. The ArrayList class implements the iterable and ListADT interfaces. The items in a list can be compared with the equals method or the compareTomethod. Complete the Java method specified below, making use of iterators must explicitly use iterators for traversing lists must not use the contains method must not modify the contents of the parameter public static ArrayList flatten (Array List > list) { //If list is null, throw a NullPointerException //If list is empty, return a new empty list. //Otherwise create and return a new list that contains the objects contained in //any of the lists contained in list, removing duplicate items. The order of //items in the returned list should be the same as the order in which they //first appear in the original list. //Example: list: [[1, 2, 3], [4, 3, 6], [1, 5]] result: [1, 2, 3, 4, 6, 5]