def test_error(self):
        """
        StdioOnnaStick created with isError=True log messages as errors.
        """
        stdio = log.StdioOnnaStick(isError=True)
        stdio.write("log 1\n")
        self.assertTrue(self.resultLogs[0]['isError'])

        StdioOnnaStick created with isError=True log messages as errors.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_log.py