class_docstr: Metaclass that ensures a private constructor for _StatefulGraphModule
class_docstr_tok: ["Metaclass","that","ensures","a","private","constructor","for","_StatefulGraphModule"]
code: def __call__(cls, *args, **kwargs):
      raise TypeError(
          f"{cls.__module__}.{cls.__qualname__} has no public constructor. "
      )
  
file_path: pytorch/torch/export/_unlift.py
imports: import copy
  import torch
  import torch.utils._pytree
  from torch._export.utils import _check_input_constraints_pre_hook
  from torch.fx.graph import _PyTreeCodeGen, _PyTreeInfo
  from .exported_program import ExportedProgram
label_desc: Use image node_id 1 for calling the _StatefulGraphModuleFactory obj's underlying member method code with example usage: obj.__call__(cls) without return types