# Last `check` warnings.
	#
	#     var tpl = new TemplateString("Hello %FIRSTNAME%, %LASTNAME%!")
	#     tpl.check
	#     assert tpl.warnings.length == 2
	#     assert tpl.warnings[0] == "No replacement for macro %FIRSTNAME% at (6:16)"
	#     assert tpl.warnings[1] == "No replacement for macro %LASTNAME% at (19:28)"
	#     tpl.replace("FIRSTNAME", "Corben")
	#     tpl.replace("LASTNAME", "Dallas")
	#     tpl.check
	#     assert tpl.warnings.is_empty
	var warnings = new Array[String]