input: Write a python function to retrieve the average response time of successful requests from a Redis list.
  assert get_avg_response_time([1.0, 2.0, 3.0, 4.0, 5.0]) == 3.0
  assert get_avg_response_time([10.0, 20.0, 30.0]) == 20.0
  assert get_avg_response_time([]) == 0
output: def get_avg_response_time(response_times):
      if not response_times:
          return 0
      return sum(response_times) / len(response_times)