code: def _model_exists_or_err(self):
      invalidInputError(
          self.ie_network is not None,
          "self.ie_network shouldn't be None.",
      )
  
imports: from pathlib import Path
  from tempfile import TemporaryDirectory
  from typing import List, Union
  from openvino.runtime import Core
  from bigdl.nano.utils.common import invalidInputError, _flatten, invalidOperationError
  from openvino.runtime import Model
  from openvino.runtime import AsyncInferQueue
  import numpy
  from datetime import datetime
  from .utils import save, OpenVINO_LESS_2022_3
label_desc: Use image node_id 16 for calling the OpenVINOModel obj's underlying member method code with example usage: obj._model_exists_or_err() without return types