Export the TorchScript IR graph to ONNX, with the inputs,
      parameters and export options recorded in this object. Then
      verify the exported ONNX graph against the original TorchScript
      IR graph under the provided verification options.
  Parameters:
     **options** (*VerificationOptions*) -- The verification
     options.

  Returns:
     The AssertionError raised during the verification. Returns
     None if no error is raised. onnx_graph: The exported ONNX
     graph in TorchScript IR format. onnx_outs: The outputs from
     running exported ONNX model under the onnx backend in
     *options*. pt_outs: The outputs from running the TorchScript
     IR graph.

  Return type:
     error
