docstr: Returns an empty in memory mlmd store.
docstr_tok: ["Returns","an","empty","in","memory","mlmd","store","."]
code: def _get_empty_metadata_store(self):
      """Returns an empty in memory mlmd store."""
      empty_db_config = metadata_store_pb2.ConnectionConfig()
      empty_db_config.fake_database.SetInParent()
      return mlmd.MetadataStore(empty_db_config)
  
imports: import os
  import uuid
  import ml_metadata
  import tensorflow_model_analysis
  from absl.testing import absltest
  from ml_metadata.proto import metadata_store_pb2
  from model_card_toolkit.model_card import ModelCard, PerformanceMetric
  from model_card_toolkit.utils import tf_utils
  from model_card_toolkit.utils.testdata import tf_testdata_utils
label_desc: Use image node_id 2 for calling the TfUtilsTest obj's underlying member method code with example usage: obj._get_empty_metadata_store() and returns: mlmd