# Build `mensure` if is not exist and return it
	private fun build_ensure: MEnsure
	do
		var m_mensure = self.mensure
		# build a new `MEnsure` contract
		if m_mensure == null then m_mensure = new MEnsure(intro_mclassdef, "_ensure_{name}", intro_mclassdef.location, public_visibility)
		self.mensure = m_mensure
		return m_mensure
	end