interface IA

	pass


class A
	implements IA

	get name as String
		return .getType.name


class B
	inherits A
	
	pass
	
	
extend A

	def foo as String
		return 'foo'


extend IA

	def bar as String
		return 'bar'


class Program

	def main is shared

		a = A()
		assert a.name == 'A'
		assert a.foo == 'foo'
		assert a.bar == 'bar'  # test interface extension
		
		b = B()
		assert b.name == 'B'
		assert b.foo == 'foo'  # test class inheritance
		assert b.bar == 'bar'  # test base class to interface extension