Why Does ArrayDeque class doesnot provide implementation of all the abstract methods declared in deque Interface?

Question

Why Does ArrayDeque class doesnot provide implementation of the following abstract methods declared in deque Interface? - descendingIterator, peekFirst, peekLast, pollFirst, pollLast .

As per the best of my knowledge if a class implements an Interface it has to provide implementation of all the abstract methods of that Interface otherwise the class is declared as abstract class.

Reference(Link) : https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/ArrayDeque.html