class_docstr: A data class to hold images of different sizes in a batch.
  
  It contains `tensors` to hold padded images to the maximum size and `mask` to
  indicate the actual image region of each padded image
code: def decompose(self):
      return self.tensors, self.mask
  
imports: from typing import List
  import torch
  from torch import Tensor
label_desc: Use image node_id 3 for calling the NestedTensor obj's underlying member method code with example usage: obj.decompose() and returns: self,  self