code: def test_get_best_trials(self):
      self._tuner_with_hparams()
  
      self.mock_client.list_trials.return_value = [
          {
              "name": "1",
              "state": "COMPLETED",
              "parameters": [
                  {"parameter": "learning_rate", "floatValue": 0.01}
              ],
              "finalMeasurement": {
                  "stepCount": "3",
                  "metrics": [{"metric": "val_acc", "value": 0.7}],
              },
              "trial_infeasible": False,
              "infeasible_reason": None,
          },
          {
              "name": "2",
              "state": "COMPLETED",
              "parameters": [
                  {"parameter": "learning_rate", "floatValue": 0.001}
              ],
              "finalMeasurement": {
                  "stepCount": "3",
                  "metrics": [{"metric": "val_acc", "value": 0.9}],
              },
              "trial_infeasible": False,
              "infeasible_reason": None,
          },
      ]
      trials = self.tuner.oracle.get_best_trials(num_trials=2)
  
      self.mock_client.list_trials.assert_called_once()
  
      self.assertEqual(len(trials), 2)
      self.assertEqual(trials[0].trial_id, "2")
      self.assertEqual(trials[1].trial_id, "1")
      self.assertEqual(trials[0].score, 0.9)
      self.assertEqual(trials[0].best_step, 3)
  
imports: import os
  import time
  from keras_tuner.engine import hypermodel
  from keras_tuner.engine import hyperparameters
  from keras_tuner.engine import oracle
  from keras_tuner.engine import trial
  from keras_tuner.engine import tuner
  import mock
  import tensorflow
  from tensorboard.plugins.hparams import api
  from tensorflow_cloud.core import deploy
  from tensorflow_cloud.core import machine_config
  from tensorflow_cloud.core import validate
  from tensorflow_cloud.tuner import cloud_fit_client
  from tensorflow_cloud.tuner import tuner
  from tensorflow_cloud.tuner.tuner import vizier_client
  from tensorflow_cloud.utils import google_api_client
  from tensorflow_cloud.utils import tf_utils
label_desc: Use image node_id 21 for calling the CloudTunerTest obj's underlying member method code with example usage: obj.test_get_best_trials() without return types