class_docstr: A base class of unified devices.
  
  Chainer has the following concrete implementations:
  
  - :class:`chainer.backend.CpuDevice`
  - :class:`chainer.backend.GpuDevice`
  - :class:`chainer.backend.Intel64Device`
  - :class:`chainer.backend.ChainerxDevice`
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docstr: A dummy definition that simply raises RuntimeError.
  
  :meth:`chainer.using_device` should be used instead.
docstr_tok: ["A","dummy","definition","that","simply","raises","RuntimeError",".",":","meth",":","`","chainer.using_device","`","should","be","used","instead","."]
code: def __enter__(self):
      """A dummy definition that simply raises RuntimeError.
  
      :meth:`chainer.using_device` should be used instead.
      """
      raise RuntimeError(
          "Device class does not support runtime context using `with` "
          "statement. Use chainer.using_device instead."
      )
  
label_desc: Use image node_id 5 for calling the Device obj's underlying member method code with example usage: obj.__enter__() without return types