I was assuming the log() method was also part of the framework, and that this was just a framework-level excerpt... ;) Perhaps such a core Log class could use

I was assuming the log() method was also part of the framework, and that this was just a framework-level excerpt... ;) Perhaps such a core Log class could use a separate createLogMessage() method (or formatMessage() as I'd probably name it) that could be overridden in a subclass more easily than overriding the entire log() method. I definitely agree that the API design and finding that balance is a big part of what makes coding an artform!