Print to stdout msg followed by the runtime.

        When true, do_reset will result in a reset of start time.

def report(self, msg, do_reset=False, file=sys.stdout):
        """Print to stdout msg followed by the runtime.

        When true, do_reset will result in a reset of start time.

        """
        print >> file, "%s (%s s)" % (msg, time.time() - self.start)
        if do_reset:
            self.start = time.time()