docs: def cmAccuracy(cm):
      """
      Calculates accuracy using :class:`~ignite.metrics.ConfusionMatrix` metric.
      Args:
          cm (ConfusionMatrix): instance of confusion matrix metric
  
      Returns:
          MetricsLambda
      """
      # Increase floating point precision
      cm = cm.type(torch.float64)
      return cm.diag().sum() / (cm.sum() + 1e-15)