extend IDictionary<of TK, TV>

	def lastValue as TV
		keys = List<of TK>(.keys)
		keys.sort
		return this[keys[keys.count-1]]


class P

	def main is shared

		d = {
			'a': 1,
			'b': 2,
			'z': 3,
			'c': 4,
			'd': 5,
		}
		
		assert d.lastValue == 3