Implement a priority queue using a DoublyLinkedList where the
node with the highest priority (key) is the right-most node.
The remove (de-queue) operation returns the node with the highest
priority (key).
If displayForward() displays List (first-->last) : 10 30 40
55
remove() would return the node with key 55.
Demonstrate by inserting keys at random, displayForward(), call
remove then displayForward() again.
You will then attach a modified DoublyLinkedList.java (to contain
the new priorityInsert(long key) and
priorityRemove() methods), and a driver...