code: def test_no_class(self) -> None:
      size = (30, 20)
      summarizer = ClassSummarizer(stats=CommonStats())
      for _ in range(10):
          x = torch.randn(size)
          summarizer.update(x)
  
      summ = summarizer.summary
      self.assertIsNotNone(summ)
      self.assertIsInstance(summ, dict)
      for key in summ:
          self.assertTrue(summ[key].size() == size)
  
      self.assertIsNotNone(summarizer.class_summaries)
      self.assertIsInstance(summarizer.class_summaries, dict)
      self.assertEqual(len(summarizer.class_summaries), 0)
  
file_path: captum/tests/attr/test_class_summarizer.py
imports: import torch
  from captum.attr import ClassSummarizer, CommonStats
  from tests.helpers.basic import BaseTest
label_desc: Use image node_id 3 for calling the Test obj's underlying member method code with example usage: obj.test_no_class() without return types