docstr: Returns accuracy metric value for all model outputs. 
docstr_tok: ["Returns","accuracy","metric","value","for","all","model","outputs","."]
code: def avg_value(self):
      """Returns accuracy metric value for all model outputs."""
      return {self._name: np.ravel(self._matches).mean()}
  
imports: import os
  import json
  import random
  from PIL import Image
  import numpy
  from compression.api import DataLoader, Metric
  from torchvision.transforms import transforms
label_desc: Use image node_id 3 for calling the Accuracy obj's underlying member method code with example usage: obj.avg_value() and returns: dict