code: def test_std_of_l2_normalized_collapsed(self):
      z = torch.ones(BATCH_SIZE, DIMENSION)  # collapsed output
      self.assertEqual(debug.std_of_l2_normalized(z), 0.0)
  
file_path: lightly/tests/utils/test_debug.py
imports: import math
  import unittest
  import numpy
  import torch
  from PIL import Image
  from lightly.data import collate
  from lightly.utils import debug
label_desc: Use image node_id 2 for calling the TestDebug obj's underlying member method code with example usage: obj.test_std_of_l2_normalized_collapsed() without return types