code: def test_export_external_converters_overwrite(
      tmpdir, check_model_expect
  ):
      path = str(tmpdir)
  
      model = chainer.Sequential(chainer.functions.sigmoid)
      x = input_generator.positive_increasing(2, 5)
  
      def custom_converter(params):
          return (
              onnx_helper.make_node(
                  "Tanh", params.input_names, params.output_names
              ),
          )
  
      addon_converters = {"Sigmoid": custom_converter}
      export_testcase(
          model, x, path, external_converters=addon_converters
      )
  
      tanh_outputs = chainer.functions.tanh(x).array
      output_path = os.path.join(path, "test_data_set_0", "output_0.pb")
      onnx_helper.write_tensor_pb(
          output_path, "", tanh_outputs
      )  # overwrite
  
      check_model_expect(path)
  
file_path: chainer/tests/onnx_chainer_tests/test_external_converter.py
imports: import os
  import chainer
  from chainer import testing
  import numpy
  import onnx
  import pytest
  from onnx_chainer import export_testcase
  from onnx_chainer import onnx_helper
  from onnx_chainer.testing import input_generator
label_desc: Use image node_id 1 for calling a global function with example usage: test_export_external_converters_overwrite(tmpdir, check_model_expect) and returns: onnx_helper