class_docstr: Structure that holds a list of images (of possibly
  varying sizes) as a single tensor.
  This works by padding the images to the same size,
  and storing in a field the original sizes of each image
docstr: Effective batch size. For multi-crop augmentations,
  (as in SwAV https://arxiv.org/abs/2006.09882) this returns N * num_crops.
  Otherwise returns N.
code: def __len__(self) -> int:
      """
      Effective batch size. For multi-crop augmentations,
      (as in SwAV https://arxiv.org/abs/2006.09882) this returns N * num_crops.
      Otherwise returns N.
      """
      return len(self.tensor)
  
file_path: vissl/vissl/data/collators/collator_helper.py
imports: from typing import List, Tuple
  import torch
label_desc: Use image node_id 2 for calling the MultiDimensionalTensor obj's underlying member method code with example usage: obj.__len__() and returns: len