code: def stack(self, preds, labels):
      # calculate accuracy
      preds = torch.stack(preds)
      labels = torch.stack(labels)
      return preds, labels
  
imports: from ..core import BaseINCMetric
  import torch
label_desc: Use image node_id 1 for calling the PytorchINCMetric obj's underlying member method code with example usage: obj.stack(preds, labels) and returns: preds,  labels