# Resolve the entity reference or return `null`.
	private fun resolve_reference(name: String): nullable String do
		if name == "lt" then
			return "<"
		else if name == "gt" then
			return ">"
		else if name == "amp" then
			return "&"
		else if name == "quot" then
			return "\""
		else if name == "apos" then
			return "'"
		else
			return null
		end
		# TODO: Support non-builtin entities
	end