facebook/tornado — pull request #958 by mooosu (2013-12-19 17:09:46+00:00)
Title: to specify formatter by option --formatter=mylog.myFormatter;define get_prefix can override in subclass

sometimes we wanna make trivial changes to log output but we do not want to reimplement tornado.log.LogFormatter,we just need a subclass and let tornado know how to find it.