code: def test_detach(self):
      self.toy_solver.bounds.requires_grad_(True)
      try:
          other = self.toy_solver.detach()
          self.assertEqualMXNBPB(self.toy_solver, other)
          for key, a in self.toy_solver.asdict().items():
              if a is None or isinstance(a, int):
                  continue
              b = getattr(other, key)
              self.assertFalse(a is b)
  
          with self.assertRaisesRegex(
              RuntimeError, "does not have a grad_fn"
          ):
              other.bounds.sum().backward()
      finally:
          self.toy_solver.bounds.requires_grad_(False)
  
imports: from __future__ import annotations
  from copy import deepcopy
  from functools import partial
  from itertools import count
  from typing import Any, Callable, Dict, Optional, Sequence, Tuple, Union
  from unittest.mock import patch
  import torch
  from botorch.utils.probability.linalg import PivotedCholesky
  from botorch.utils.probability.mvnxpb import MVNXPB
  from botorch.utils.testing import BotorchTestCase
  from linear_operator.utils.errors import NotPSDError
  from torch import Tensor
label_desc: Use image node_id 11 for calling the TestMVNXPB obj's underlying member method code with example usage: obj.test_detach() without return types