@Override
		public int lowerIndex(V element) {
			if (root == null) {
				return -1;
			}
			Node n = searchValue(element, SearchMode.LOWER);
			if (n == null) {
				return -1;
			}
			return n.computeIndex();
		}
A public view of the map as a list of values

This view implements {@link SortedList} and {@link Deque}, since an ordered collection ought
to behave like a list, and since this implementation is meant to be used as a dynamic-cost
priority queue.

Generally, only the removal mutation methods are supported, all others are not supported.
Ghidra/Framework/Generic/src/main/java/ghidra/generic/util/datastruct/TreeValueSortedMap.java