code: def _load_stats(self):
          
          for attempt in range(0, 3):
              try:
                  with self.stats_file.open() as f:
                      return json.load(f)
              except ValueError:
                  # If we failed to parse the JSON, it's possible that the
                  # webpack process is writing to it concurrently and it's in a
                  # bad state. Sleep and retry.
                  if attempt < 2:
                      time.sleep(attempt * 0.2)
                  else:
                      raise
              except IOError:
                  raise IOError(
                      "Could not read stats file {0}. Make sure you are using the "
                      "webpack-bundle-tracker plugin" .format(self.stats_file))
docs: Load the webpack-stats file