https://twetch.app/t/2db25d5a0f20d81115786daf8f2799b2a677ab…

https://twetch.app/t/2db25d5a0f20d81115786daf8f2799b2a677ab8d085c47d99951a30d1377f33a : In computer programming, a sentinel node is a specifically designated node used with linked lists and trees as a traversal path terminator.