class Foo<of TBar>
	where TBar must be Bar

	def add(bar as TBar)
		assert bar.value>40


class Bar

	get value as int
		return 42


class Baz
	inherits Bar

	get value as int is override
		return 43


class Test

	def main is shared
		f as Foo<of Bar> = Foo<of Bar>()
		f.add(Bar())
		f.add(Baz())

		g as Foo<of Baz> = Foo<of Baz>()
		g.add(Baz())