def test_logErrorLogsErrorNoRepr(self):
        """
        The text logged by L{defer.logError} has no repr of the failure.
        """
        output = []

        def emit(eventDict):
            output.append(log.textFromEventDict(eventDict))

        log.addObserver(emit)

        error = failure.Failure(RuntimeError())
        defer.logError(error)
        self.flushLoggedErrors(RuntimeError)

        self.assertTrue(output[0].startswith("Unhandled Error\nTraceback "))

        The text logged by L{defer.logError} has no repr of the failure.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_defer.py