class Test

	def main is shared
		c as List<of String>?

		x as int = 0
		if c
			x = 1
		assert x==0

		c = List<of String>()  # list literals haven't been tested yet
		c.add('a')
		c.add('b')
		if c
			x = 2
		assert x==2

		if c is not nil
			x = 3
		assert x==3

		if c<>nil
			x = 4
		assert x==4