code: def testInvalidPbtxt(self):
      with self.assertRaisesRegex(
          errors.InvalidArgumentError, "Could not parse input proto"
      ):
          mlir.convert_graph_def("some invalid proto")
  
imports: import os
  from tensorflow.python.compiler.mlir import mlir
  from tensorflow.python.eager import def_function
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import errors
  from tensorflow.python.framework import tensor_spec
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import logging_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.platform import resource_loader
  from tensorflow.python.platform import test
  from tensorflow.python.pywrap_mlir import experimental_tflite_to_tosa_bytecode
  from tensorflow.python.pywrap_mlir import import_graphdef
label_desc: Use image node_id 2 for calling the MLIRGraphDefImportTest obj's underlying member method code with example usage: obj.testInvalidPbtxt() without return types