<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _check_time_backwards(self):
 """Make sure a clock reset didn't cause time to go backwards """


        now = time.time()

        if now < self.start:
            self.start = now
            self.end = self.start + self.length