code: def test_fix(self) -> None:
      fix1 = self.mf[type(self.bn1)](self.bn1)
      fix2 = self.mf[type(self.bn2)](self.bn2)
      fix3 = self.mf[type(self.bn3)](self.bn3)
      fixs = self.mf[type(self.bns)](self.bns)
  
      self.assertTrue(isinstance(fix1, nn.GroupNorm))
      self.assertTrue(isinstance(fix2, nn.GroupNorm))
      self.assertTrue(isinstance(fix3, nn.GroupNorm))
      self.assertTrue(isinstance(fixs, nn.GroupNorm))
  
file_path: opacus/opacus/tests/validators/batch_norm_test.py
imports: import unittest
  import torch.nn
  from opacus.validators.errors import ShouldReplaceModuleError
  from opacus.validators.module_validator import ModuleValidator
label_desc: Use image node_id 3 for calling the BatchNormValidator_test obj's underlying member method code with example usage: obj.test_fix() without return types