code: def turn_left(self, angle_degrees, rate=RATE):
          
          flight_time = angle_degrees / rate
  
          self.start_turn_left(rate)
          time.sleep(flight_time)
          self.stop()
docs: Turn to the left, staying on the spot
  
          :param angle_degrees: How far to turn (degrees)
          :param rate: The trurning speed (degrees/second)
          :return: