def METHOD_NAME(self) -> None:
    """
    If the C{"log_failure"} key exists in an event, and contains an object
    that raises when you call its C{getTraceback()}, then the observer
    appends a message noting the problem, instead of raising.
    """
    with StringIO() as fileHandle:
        observer = textFileLogObserver(fileHandle)
        event = dict(log_failure=object())  # object has no getTraceback()
        observer(event)
        output = fileHandle.getvalue()
        expected = "(UNABLE TO OBTAIN TRACEBACK FROM EVENT)"
        self.assertIn(expected, output)