code: def pause(self):
  		
  		if self.status == RUNNING:
  			self.status = PAUSED
  			self.previous_intervals.append(time.time() - self.interval_start)
  			self.current_interval_duration = 0.0
  		elif self.status == PAUSED:
  			self.interval_start = time.time()
  			self.status = RUNNING
docs: Pauses the clock to continue running later.
  		Saves the duration of the current interval in the previous_intervals 
  		list.