Кольцевой связный список (circular linked list)

Тот же ****список, но:

• LastNode.next = head
• FirstNode.previous = tail (only for doubly linked list)

Получается такое “кольцо”:

Circular singly linked list. https://www.tutorialspoint.com/data_structures_algorithms/circular_linked_list_algorithm.htm

Circlular doubly linked list. https://www.aiophotoz.com/photos/data-structures-in-python-circular-linked-lists-is-circular-linked.html