code: def _make_model_acos_exp_topk():  # type: (...) -> ModelProto
      """
      make a very simple model for testing: input->clip->exp->topk->2 outputs
      """
      inputs = [
          ("input0", (10,), TensorProto.FLOAT),
          ("K", (1,), TensorProto.INT64),
      ]
      outputs = [
          ("output_values", (3,), TensorProto.FLOAT),
          ("output_indices", (3,), TensorProto.INT64),
      ]
      acos = helper.make_node(
          "Acos", inputs=[inputs[0][0]], outputs=["acos_out"]
      )
      exp = helper.make_node(
          "Exp", inputs=[acos.output[0]], outputs=["exp_out"]
      )
      topk = helper.make_node(
          "TopK",
          inputs=[exp.output[0], inputs[1][0]],
          outputs=[outputs[0][0], outputs[1][0]],
          axis=0,
      )
      return _onnx_create_model([acos, exp, topk], inputs, outputs)
  
file_path: turicreate/src/external/coremltools_wrap/coremltools/coremltools/converters/onnx/_tests/test_custom_layers.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import unittest
  from coremltools._deps import _HAS_ONNX, MSG_ONNX_NOT_FOUND
  from coremltools.proto import NeuralNetwork_pb2
label_desc: Use image node_id 1 for calling a global function with example usage: _make_model_acos_exp_topk() and returns: _onnx_create_model