code: def load_testdata(
      filename: str,
      proto_class: Type[_P] = placeholder_pb2.PlaceholderExpression,
  ) -> _P:
      test_pb_filepath = os.path.join(
          os.path.dirname(__file__), "testdata", filename
      )
      with open(test_pb_filepath) as text_pb_file:
          return text_format.ParseLines(text_pb_file, proto_class())
  
imports: import os
  from typing import Type, TypeVar
  from absl.testing import parameterized
  import tensorflow
  from tfx.dsl.placeholder import placeholder
  from tfx.proto.orchestration import placeholder_pb2
  from tfx.types import channel_utils
  from tfx.types import standard_artifacts
  from tfx.types.artifact import Artifact
  from tfx.types.artifact import Property
  from tfx.types.artifact import PropertyType
  from tfx.types.channel import Channel
  from google.protobuf import message
  from google.protobuf import text_format
label_desc: Use image node_id 1 for calling a global function with example usage: load_testdata(filename, proto_class) and returns: text_format