class_docstr: This class tests if optuna is in effect for create_reduction_func()
class_docstr_tok: ["This","class","tests","if","optuna","is","in","effect","for","create_reduction_func","(",")"]
code: def tearDown(self):
      _accelerator.set_routine_accelerators(self.old_routines)
      _accelerator.set_reduction_accelerators(self.old_reductions)
  
imports: import os
  import tempfile
  import unittest
  from unittest import mock
  import pytest
  import cupy
  from cupy import testing
  from cupy._core import _accelerator
label_desc: Use image node_id 2 for calling the TestOptimizeBackends obj's underlying member method code with example usage: obj.tearDown() without return types