code: def test_experimental_class_method(self):
      with warnings.catch_warnings(record=True) as w:
          warnings.simplefilter("always")
          C.class_method()
  
      self.assertEqual(len(w), 1)
      self.assertIs(w[0].category, FutureWarning)
      self.assertIn(
          "C.class_method is experimental.", str(w[0].message)
      )
  
imports: import unittest
  import warnings
  import chainer
  from chainer import testing
  from chainer import utils
label_desc: Use image node_id 7 for calling the TestExperimental obj's underlying member method code with example usage: obj.test_experimental_class_method() without return types