docstr: :return: list of inputs
docstr_tok: [":","return",":","list","of","inputs"]
code: def _extract_model_inputs(self):
      """
      :return: list of inputs
      """
      assert len(self._input_list) == 2, "Sub should have 2 inputs"
      return [self._to_zoo_input(oi) for oi in self._input_list]
  
imports: from zoo.pipeline.api.onnx.mapper.operator_mapper import OperatorMapper
label_desc: Use image node_id 2 for calling the SubMapper obj's underlying member method code with example usage: obj._extract_model_inputs() and returns: unknown