@capture_logging(None)
    def test_writeTracebackDefaultLogger(self, logger):
        def raiser():
            raise RuntimeError("because")
        try:
            raiser()
        except Exception:
            writeTraceback()

        message = logger.messages[0]
        assertContainsFields(self, message,
                             {"message_type": "eliot:traceback"})
        logger.flushTracebacks(RuntimeError)
L{writeTraceback} writes to the default log, if none is
dataset/ETHPy150Open ClusterHQ/eliot/eliot/tests/test_traceback.py/TracebackLoggingTests.test_writeTracebackDefaultLogger