@Override
	public long previous() {
        if (hasPrevious()) {
			doesHavePrevious = false;
            doesHaveNext = true;
			return current;
		}

		throw new NoSuchElementException("No more indexes.");
    }
Returns the previous index in the iterator.
Ghidra/Framework/Generic/src/main/java/ghidra/util/map/LongIteratorImpl.java