class_docstr: Metaclass for ``DependentBackend``.
  To ensure the backend config is unique in diverse threads for multiprocessing runtime,
  the backend config is instantiated in the metaclass during interpretation phase.
class_docstr_tok: ["Metaclass","for","``","DependentBackend","``",".","To","ensure","the","backend","config","is","unique","in","diverse","threads","for","multiprocessing","runtime",",","the","backend","config","is","instantiated","in","the","metaclass","during","interpretation","phase","."]
code: def __new__(
      mcs,
      name: str,
      bases: _typing.Tuple[type, ...],
      namespace: _typing.Dict[str, _typing.Any],
  ):
      for base in bases:
          if isinstance(base, _DependentBackendMetaclass):
              strings = (
                  f"{base} is instance of Metaclass {_DependentBackendMetaclass}",
                  f"and MUST not be inherited/extended by <{name}> to construct",
              )
              raise TypeError(" ".join(strings))
      instance = super(_DependentBackendMetaclass, mcs).__new__(
          mcs, name, bases, namespace
      )
      return instance
  
imports: import os
  import logging
  import typing
label_desc: Use image node_id 1 for calling the _DependentBackendMetaclass obj's underlying member method code with example usage: obj.__new__(mcs, name, bases, namespace) and returns: instance