class_docstr: At the end of the entire stream of experiences, this plugin metric
  reports the average accuracy over all patterns seen in all experiences.
  This metric only works at eval time.
class_docstr_tok: ["At","the","end","of","the","entire","stream","of","experiences",",","this","plugin","metric","reports","the","average","accuracy","over","all","patterns","seen","in","all","experiences",".","This","metric","only","works","at","eval","time","."]
code: def __str__(self):
      return "Top1_Acc_Stream"
  
imports: from typing import List, Optional, Union, Dict
  import torch
  from torch import Tensor
  from avalanche.evaluation import Metric, GenericPluginMetric
  from avalanche.evaluation.metrics.mean import Mean
  from collections import defaultdict
label_desc: Use image node_id 2 for calling the StreamAccuracy obj's underlying member method code with example usage: obj.__str__() and returns: str