class_docstr: At the end of the entire stream of experiences, this metric reports the
  average loss over all patterns seen in all experiences.
  This plugin metric only works at eval time.
class_docstr_tok: ["At","the","end","of","the","entire","stream","of","experiences",",","this","metric","reports","the","average","loss","over","all","patterns","seen","in","all","experiences",".","This","plugin","metric","only","works","at","eval","time","."]
docstr: Creates an instance of StreamLoss metric
code: def __init__(self):
      """
      Creates an instance of StreamLoss metric
      """
      super(StreamLoss, self).__init__(
          reset_at="stream", emit_at="stream", mode="eval"
      )
  
imports: from typing import List, Dict
  import torch
  from torch import Tensor
  from avalanche.evaluation import PluginMetric, Metric, GenericPluginMetric
  from avalanche.evaluation.metrics.mean import Mean
  from avalanche.evaluation.metric_utils import phase_and_task
  from collections import defaultdict
label_desc: Use image node_id 1 to create a new StreamLoss object from inherited base classes: LossPluginMetric with example: obj = StreamLoss()