E poll()
Retrieves and removes the head (first element) of this list
E pollFirst()
Retrieves and removes the first element of this list, or returns null if this list is empty.
E pollLast()
Retrieves and removes the last element of this list, or returns null if this list is empty.
E pop()
Pops an element from the stack represented by this list.
void push(E e)
Pushes an element onto the stack represented by this list.