Question: What are the methods of Java Deque?
Answer: Method:  add(E e) 
Description: This method is used to insert a specified element into the queue represented by the deque

Method:   addAll(Collection<? Extends E>c)
Description: Adds all the elements in the specified collection at the end of the deque.

Method:   addFirst(E e)
Description: Inserts the specified element at the front of the deque.

Method:  addLast(E e) 
Description: Inserts the specified element at the end of the deque.

Method:   contains(object o)
Description: Returns true if the deque contains the specified element.

Method:   descendingIterator()
Description: Returns an iterator over the elements in reverse sequential order.

Method:   element()
Description: Retrieves the head of the queue represented by the deque.

Method:   getFirst()
Description: Retrieves but does not remove the first element of the deque

Method:   getLast()
Description: Retrieves but does not remove the last element of the deque.

Method:iterator()   
Description: Returns an iterator over the element in the deque in a proper sequence.

Method: offer(E e)  
Description: Inserts the specified element into the deque, returning true upon success and false if no space is available.

Method:offerFirst()   
Description: Inserts the specified element at the front of the deque unless it violates the capacity restriction.

Method:   offerLast()
Description: Inserts the specified element at the end of the deque unless it violates the capacity restriction.

Method:  peek() 
Description: Retrieves but does not move the head of the queue represented by the deque or may return null if the deque is empty.

Method:  peekFirst() 
Description: Retrieves but does not move the first element of the deque or may return null if the deque is empty.

Method:   peekLast()
Description: Retrieves but does not move the last element of the deque or may return null if the deque is empty.

Method:  poll() 
Description: Retrieves and remove the head of the queue represented by the deque or may return null if the deque is empty.

Method: pollFirst()  
Description: Retrieves and remove the first element of the deque or may return null if the deque is empty.

Method:  pollLast() 
Description: Retrieves and remove the last element of the deque or may return null if the deque is empty.

Method:  pop() 
Description: Pops an element from the stack represented by the deque.

Method:   push()
Description: Pushes an element onto the stack represented by the deque.

Method:   remove()
Description: Retrieves and remove the head of the queue represented by the deque.

Method:   remove(Object o)
Description: Removes the first occurrence of the specified element from the deque.

Method:   removeFirst()
Description: Retrieves and remove the first element from the deque.

Method:  removeFirstOccurrence(Object o) 
Description: Remove the first occurrence of the element from the deque.

Method:   removeLast()
Description: Retrieve and remove the last element from the deque.

Method: removeLastOccurrence(Object o)  
Description: Remove the last occurrence of the element from the deque.

Method:   size()
Description: Returns the total number of elements in the deque.