code: def __get_total_response_time(meta_datas_expanded):
      
      try:
          response_time = 0
          for meta_data in meta_datas_expanded:
              response_time += meta_data["stat"]["response_time_ms"]
  
          return "{:.2f}".format(response_time)
  
      except TypeError:
          # failure exists
          return "N/A"
docs: caculate total response time of all meta_datas