code: def test_unset_backend():
      for backend_str in _available_frameworks():
          ivy.set_backend(backend_str)
  
      ivy.unset_backend()
      ivy.utils.assertions.check_equal(
          ivy.backend_stack, [], as_array=False
      )
  
file_path: ivy/ivy_tests/test_ivy/test_misc/test_backend_utils/test_backend_handler.py
imports: from packaging import version
  import pytest
  import importlib
  import types
  import numpy
  import ivy
  from ivy.utils.backend.handler import _backend_dict
  from ivy_tests.test_ivy.helpers.available_frameworks import _available_frameworks
label_desc: Use image node_id 10 for calling a global function with example usage: test_unset_backend() without return types