code: def test_check_string_tensor(self) -> None:
      tensor = TensorProto()
      tensor.data_type = TensorProto.STRING
      tensor.dims.append(1)
      tensor.string_data.append(b"Test")
      checker.check_tensor(tensor)
  
      del tensor.string_data[:]
      tensor.raw_data = b"Test"
      # string data should not be stored in raw_data field
      self.assertRaises(
          checker.ValidationError, checker.check_tensor, tensor
      )
  
imports: import os
  import tempfile
  import unittest
  from typing import Sequence
  import numpy
  import onnx.defs
  import onnx.parser
  from onnx import GraphProto, SparseTensorProto, TensorProto, checker, helper, numpy_helper, shape_inference
label_desc: Use image node_id 19 for calling the TestChecker obj's underlying member method code with example usage: obj.test_check_string_tensor() without return types