code: def validate_training_data_stats(training_data_stats):
          
          stat_keys = list(training_data_stats.keys())
          valid_stat_keys = ["means", "mins", "maxs", "stds", "feature_values", "feature_frequencies"]
          missing_keys = list(set(valid_stat_keys) - set(stat_keys))
          if len(missing_keys) > 0:
              raise Exception("Missing keys in training_data_stats. Details:" % (missing_keys))
docs: Method to validate the structure of training data stats