<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:

def trigger(self):
        '''return True if we should trigger now'''
        tnow = time.time()

        if tnow < self.last_time:
            print("Warning, time moved backwards. Restarting timer.")
            self.last_time = tnow

        if self.last_time + (1.0/self.frequency) <= tnow:
            self.last_time = tnow
            return True
        return False