class_docstr: The minibatch plugin class accuracy metric.
  This metric only works at training time.
  
  This metric computes the average accuracy over patterns
  from a single minibatch.
  It reports the result after each iteration.
  
  If a more coarse-grained logging is needed, consider using
  :class:`EpochClassAccuracy` instead.
code: def __str__(self):
      return "Top1_ClassAcc_MB"
  
imports: from typing import Dict, List, Set, Union, TYPE_CHECKING, Iterable, Optional
  from collections import defaultdict, OrderedDict
  import torch
  from torch import Tensor
  from avalanche.evaluation import Metric, PluginMetric, _ExtendedGenericPluginMetric, _ExtendedPluginMetricValue
  from avalanche.evaluation.metric_utils import default_metric_name_template, generic_get_metric_name
  from avalanche.evaluation.metrics import Mean
label_desc: Use image node_id 2 for calling the MinibatchClassAccuracy obj's underlying member method code with example usage: obj.__str__() and returns: str