def _runWithoutDecoration(self, test, forceGarbageCollection=False):
        """
        Private helper that runs the given test but doesn't decorate it.
        """
        result = self._makeResult()
        # decorate the suite with reactor cleanup and log starting
        # This should move out of the runner and be presumed to be
        # present
        suite = TrialSuite([test], forceGarbageCollection)
        startTime = time.time()
        if self.mode == self.DRY_RUN:
            for single in _iterateTests(suite):
                result.startTest(single)
                result.addSuccess(single)
                result.stopTest(single)
        else:
            if self.mode == self.DEBUG:
                run = lambda: self.debugger.runcall(suite.run, result)
            else:
                run = lambda: suite.run(result)

            oldDir = self._setUpTestdir()
            try:
                self._setUpLogFile()
                run()
            finally:
                self._tearDownLogFile()
                self._tearDownTestdir(oldDir)

        endTime = time.time()
        done = getattr(result, 'done', None)
        if done is None:
            warnings.warn(
                "%s should implement done() but doesn't. Falling back to "
                "printErrors() and friends." % reflect.qual(result.__class__),
                category=DeprecationWarning, stacklevel=3)
            result.printErrors()
            result.writeln(result.separator)
            result.writeln('Ran %d tests in %.3fs', result.testsRun,
                           endTime - startTime)
            result.write('\n')
            result.printSummary()
        else:
            result.done()
        return result

        Private helper that runs the given test but doesn't decorate it.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/trial/runner.py