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`
class_docstr_tok: ["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","`"]
docstr: A dummy definition that should never be called.
docstr_tok: ["A","dummy","definition","that","should","never","be","called","."]
code: def __exit__(self, exc_type, exc_value, traceback):
      """A dummy definition that should never be called."""
      # Definition of __exit__ is needed to raise a custom error on
      # __enter__.
      pass
  
label_desc: Use image node_id 6 for calling the Device obj's underlying member method code with example usage: obj.__exit__(exc_type, exc_value, traceback) without return types