# Run NitUnit test suite for `mmodule` (if it is one).
	fun test_unit(mmodule: MModule): nullable HTMLTag do
		# is the module a test_suite?
		if not mmodule.is_test then return null
		toolcontext.info("nitunit: test-suite {mmodule}", 2)

		var tester = new NitUnitTester(self)
		var res = tester.test_module_unit(mmodule)
		return res.to_xml
	end