code: def _test_op_downgrade(self, op: str, *args, **kwargs):
      self._test_op_conversion(op, *args, **kwargs, is_upgrade=False)
  
file_path: onnx/onnx/test/version_converter/automatic_downgrade_test.py
imports: import unittest
  import automatic_conversion_test_base
  import numpy
  import parameterized
  import onnx
  from onnx import helper
label_desc: Use image node_id 1 for calling the TestAutomaticDowngrade obj's underlying member method code with example usage: obj._test_op_downgrade(op) without return types