class_docstr: Raised when the selected backend is not supported.
code: def __init__(self, msg):
      super().__init__(msg + _missing_backend)
  
file_path: hummingbird/hummingbird/ml/exceptions.py
label_desc: Use image node_id 1 to create a new MissingBackend object from inherited base classes: RuntimeError with example: obj = MissingBackend(msg)