code: def test_identity_ste(self):
      for dtype in (torch.float, torch.double):
          X = torch.rand(3, device=self.device, dtype=dtype)
          with self.assertRaises(NotImplementedError):
              IdentitySTEFunction.apply(X)
          X = X.requires_grad_(True)
          X_out = DummySTEFunction.apply(X)
          X_out.sum().backward()
          self.assertTrue(torch.equal(2 * X, X_out))
          self.assertTrue(torch.equal(X.grad, torch.ones_like(X)))
  
file_path: botorch/test/utils/test_rounding.py
imports: import torch
  from botorch.utils.rounding import approximate_round, IdentitySTEFunction, OneHotArgmaxSTE, RoundSTE
  from botorch.utils.testing import BotorchTestCase
  from torch.nn.functional import one_hot
label_desc: Use image node_id 1 for calling the TestIdentitySTEFunction obj's underlying member method code with example usage: obj.test_identity_ste() without return types