class Test

	def main is shared
		Test().run
		
	def run
		# assert List<of int>(.numbers) == [1, 2, 3]
		t = List<of int>(.numbers(0))
		assert t == [1, 2, 3]
		t = List<of int>(.numbers(1))
		assert t == [1]

	def numbers(x as int) as IEnumerable<of int>
		yield 1
		if x > 0
			yield break
		yield 2
		yield 3