code: def test_set_backend_local_threadsafe():
      pytest.importorskip("torch")
  
      global_default = tl.get_backend()
  
      with ThreadPoolExecutor(max_workers=1) as executor:
          with tl.backend_context("numpy", local_threadsafe=True):
              assert tl.get_backend() == "numpy"
              # Changes only happen locally in this thread
              assert (
                  executor.submit(tl.get_backend).result()
                  == global_default
              )
  
          # Set the global default backend
          try:
              tl.set_backend("pytorch", local_threadsafe=False)
  
              # Changed toplevel default in all threads
              assert (
                  executor.submit(tl.get_backend).result() == "pytorch"
              )
  
              with tl.backend_context("numpy", local_threadsafe=True):
                  assert tl.get_backend() == "numpy"
  
                  def check():
                      assert tl.get_backend() == "pytorch"
                      with tl.backend_context(
                          "numpy", local_threadsafe=True
                      ):
                          assert tl.get_backend() == "numpy"
                      assert tl.get_backend() == "pytorch"
  
                  executor.submit(check).result()
          finally:
              tl.set_backend(global_default, local_threadsafe=False)
              executor.submit(tl.set_backend, global_default).result()
  
          assert tl.get_backend() == global_default
          assert (
              executor.submit(tl.get_backend).result() == global_default
          )
  
imports: from concurrent.futures import ThreadPoolExecutor
  import pytest
  from time import time
  import numpy
  from scipy.linalg import svd
  from scipy import special
  import tensorly
  from ..None import backend
  from ..testing import assert_allclose, assert_array_equal, assert_equal, assert_, assert_array_almost_equal, assert_raises
  from tensorly.tenalg.svd import SVD_FUNS, svd_interface
label_desc: Use image node_id 2 for calling a global function with example usage: test_set_backend_local_threadsafe() without return types