# boolean default
class OptParam
	def main is shared
		x = OptParam()
		x.val = true
		x.foo('default')
		assert x.val == false
		x.foo('provided', true)
		assert x.val

	var val = false
	
	def foo(s as String, b = false) 
		if s == 'default'
			assert b == false
		.val = b