@Override
		public Node previous() {
			if (!hasPrevious()) {
				throw new NoSuchElementException();
			}
			if (atEnd) {
				next = tail;
				atEnd = tail == null;
			}
			else {
				cur = next = next.prev;
			}
			return cur;
		}
Construct a list iterator over the entries

A start of null implies one past the end of the list, i.e., {@code tail.next}

@param start the starting node
Ghidra/Framework/Generic/src/main/java/ghidra/generic/util/datastruct/TreeValueSortedMap.java