'Get something that can be used to log messages.
Overridable.'

@property
def log(self):

    class O(object, ):
        pass
    def pr(fmt, *args):
        print (fmt % args)
    def nopr(*args):
        pass
    o = O()
    o.warn = nopr
    o.debug = nopr
    o.error = nopr
    o.info = nopr
    return o
