human
I wrote the below code

    def formatEvent(event):
        return formatEventAsClassicLogText(event, formatTime=(lambda e: formatTime(e, timeFormat)))
    return FileLogObserver(outFile, formatEvent)

What's a good function header?
 ... Here's a good function header?
assistant
#Here's a good function header.

def textFileLogObserver(outFile, timeFormat=timeFormatRFC3339):