code: def test_experiment_without_any_hparams(self):
      actual_exp = self._experiment_from_metadata()
      self.assertIsInstance(actual_exp, api_pb2.Experiment)
      self.assertProtoEquals("", actual_exp)
  
imports: import operator
  from unittest import mock
  import tensorflow
  from google.protobuf import text_format
  from tensorboard import context
  from tensorboard.data import provider
  from tensorboard.plugins import base_plugin
  from tensorboard.plugins.hparams import api_pb2
  from tensorboard.plugins.hparams import backend_context
  from tensorboard.plugins.hparams import metadata
  from tensorboard.plugins.hparams import plugin_data_pb2
label_desc: Use image node_id 14 for calling the BackendContextTest obj's underlying member method code with example usage: obj.test_experiment_without_any_hparams() without return types