private void findNext() {

		try {
			long nextIndex = pm.getNextPropertyIndex(current);
            if (hasBoundaries && nextIndex > end) {
                doesHaveNext = false;
                return;
            }
			current = nextIndex;
            doesHaveNext = true;
            doesHavePrevious = false;

		} catch (NoSuchIndexException e) {
			return;
		}
	}
Return whether there is a next index; if there is,
"currentNext" has the value.
Ghidra/Framework/Generic/src/main/java/ghidra/util/map/LongIteratorImpl.java