This looks promising. Nothing that has never been done before, but I really like the support for baked in doctests and contracts. This kind of sugar can make a real difference in terms of quality and readability

    #from the website, because it seems to be down for many right now.

    class SmallSample
	var _random = Random() 
	def randomString(length as int, alphabet as String) as String
		require
			length > 0
			alphabet <> ''
		ensure
			result.length == length
		test
			utils = SmallSample()
			assert utils.randomString(5, 'ab').length == 5
			s = utils.randomString(1000, 'a')
			for c in s, assert c == 'a'
		body
			sb = StringBuilder()
			for i in length
			c = alphabet[_random.next(alphabet.length)]
			sb.append(c)
			return sb.toString