@@ -0,0 +1,883 @@
+import java.util.Iterator;%0A%0Apublic class DequeAPI%3CItem%3E implements Iterable%3CItem%3E %7B%0A%0A    // construct an empty deque%0A    public DequeAPI() %7B%7D                                    %0A%0A    // is the deque empty?%0A    public boolean isEmpty() %7B return  false; %7D%0A%0A    // return the number of items on the deque%0A    public int size() %7B return 0; %7D%0A    %0A    // insert the item at the front%0A    public void addFirst(Item item) %7B%7D%0A    %0A    // insert the item at the end%0A    public void addLast(Item item) %7B%7D%0A%0A    // delete and return the item at the front%0A    public Item removeFirst() %7B return null; %7D%0A    %0A    // delete and return the item at the end%0A    public Item removeLast() %7B return null; %7D%0A    %0A    // return an iterator over items in order from front to end%0A    public Iterator%3CItem%3E iterator() %7B return null; %7D%0A%0A    // unit testing%0A    public static void main(String%5B%5D args) %7B%7D%0A    %0A%7D%0A

Create DequeAPI.java