code: def normalize_batch(batch):
      # normalize using imagenet mean and std
      mean = batch.new_tensor([0.485, 0.456, 0.406]).view(-1, 1, 1)
      std = batch.new_tensor([0.229, 0.224, 0.225]).view(-1, 1, 1)
      batch = batch.div_(255.0)
      return (batch - mean) / std
  
imports: from PIL import Image
label_desc: Use image node_id 4 for calling a global function with example usage: normalize_batch(batch) and returns: unknown