code: def _getExportDir(self):
      return os.path.join(self._getTempDir(), "export_dir")
  
imports: import os
  from absl.testing import parameterized
  import apache_beam
  from apache_beam.testing import util
  import numpy
  import tensorflow
  from tensorflow_model_analysis import constants
  from tensorflow_model_analysis.api import model_eval_lib
  from tensorflow_model_analysis.eval_saved_model import testutil
  from tensorflow_model_analysis.eval_saved_model.example_trainers import dnn_classifier
  from tensorflow_model_analysis.eval_saved_model.example_trainers import fixed_prediction_estimator_extra_fields
  from tensorflow_model_analysis.eval_saved_model.example_trainers import multi_head
  from tensorflow_model_analysis.extractors import features_extractor
  from tensorflow_model_analysis.extractors import predictions_extractor
  from tensorflow_model_analysis.extractors import tfx_bsl_predictions_extractor
  from tensorflow_model_analysis.proto import config_pb2
  from tfx_bsl.tfxio import tensor_adapter
  from tfx_bsl.tfxio import test_util
  from google.protobuf import text_format
  from tensorflow_metadata.proto.v0 import schema_pb2
label_desc: Use image node_id 1 for calling the TfxBslPredictionsExtractorTest obj's underlying member method code with example usage: obj._getExportDir() and returns: os