class_docstr: Metaclass for the dummy objects. Any class inheriting from it will return the ImportError generated by
  `requires_backend` each time a user tries to access any method of that class.
code: def __getattr__(cls, key):
      if key.startswith("_") and key not in [
          "_load_connected_pipes",
          "_is_onnx",
      ]:
          return super().__getattr__(cls, key)
      requires_backends(cls, cls._backends)
  
imports: import importlib.util
  import operator
  import os
  import sys
  from collections import OrderedDict
  from itertools import chain
  from types import ModuleType
  from typing import Any, Union
  from huggingface_hub.utils import is_jinja_available
  from packaging import version
  from packaging.version import Version, parse
  from .None import logging
label_desc: Use image node_id 1 for calling the DummyObject obj's underlying member method code with example usage: obj.__getattr__(cls, key) and returns: super