code: def __init__(self):
      self.model = self.load_model()
      self.stan_fit = None
      self.newton_fallback = True
  
imports: from __future__ import absolute_import, division, print_function
  from abc import abstractmethod, ABC
  from dataclasses import dataclass
  from typing import Sequence, Tuple
  from collections import OrderedDict
  from enum import Enum
  import importlib_resources
  import platform
  import logging
label_desc: Use image node_id 1 to create a new IStanBackend object from inherited base classes: ABC with example: obj = IStanBackend()