code: def __exit__(self, typ, value, traceback):
      contexts = self._contexts.pop()
      for c in reversed(contexts):
          c.__exit__(typ, value, traceback)
  
imports: import functools
  import chainer
  from chainer import backend
  from chainer.testing import _bundle
  from chainer.testing import attr
  import chainerx
label_desc: Use image node_id 7 for calling the BackendConfig obj's underlying member method code with example usage: obj.__exit__(typ, value, traceback) without return types