code: def aggregation(self):
      return {
          "acc": mean,
      }
  
imports: import inspect
  import lm_eval.datasets.triviaqa.triviaqa
  from lm_eval.base import Task, rf
  from lm_eval.metrics import mean
label_desc: Use image node_id 14 for calling the TriviaQA obj's underlying member method code with example usage: obj.aggregation() and returns: dict