<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def log_status (self):
 """Log a status message."""

        duration = time.time() - self.start_time
        checked, in_progress, queue = self.aggregator.urlqueue.status()
        num_urls = len(self.aggregator.result_cache)
        self.logger.log_status(checked, in_progress, queue, duration, num_urls)