# Append text to element
	#
	#     var p = new HTMLTag("p")
	#     p.append("Hello")
	#     p.add(new HTMLTag("br"))
	#     p.append("World!")
	#     assert p.write_to_string      ==  "<p>Hello<br/>World!</p>"
	# Text is escaped see: core::String::html_escape
	fun append(txt: String): HTMLTag do
		add(new HTMLRaw("", txt.html_escape))
		return self
	end