code: def calc_mean_invstddev(feature):
      if len(feature.size()) != 2:
          raise ValueError(
              "We expect the input feature to be 2-D tensor"
          )
      mean = feature.mean(0)
      var = feature.var(0)
      # avoid division by ~zero
      eps = 1e-8
      if (var < eps).any():
          return mean, 1.0 / (torch.sqrt(var) + eps)
      return mean, 1.0 / torch.sqrt(var)
  
imports: import torch
label_desc: Use image node_id 1 for calling a global function with example usage: calc_mean_invstddev(feature) and returns: mean,  unknown, mean,  unknown