class_docstr: Tune driver
class_docstr_tok: ["Tune","driver"]
docstr: get a list of best k trials
  :params k: top k
  :return: trials list
docstr_tok: ["get","a","list","of","best","k","trials",":","params","k",":","top","k",":","return",":","trials","list"]
code: def get_best_trials(self, k=1):
      """
      get a list of best k trials
      :params k: top k
      :return: trials list
      """
      sorted_trials = RayTuneSearchEngine._get_sorted_trials(
          self.trials, metric=self.metric_name, mode=self.mode
      )
      best_trials = sorted_trials[:k]
      return [self._make_trial_output(t) for t in best_trials]
  
imports: import ray
  from ray import tune
  import os
  from zoo.orca.automl.search.base import SearchEngine, TrialOutput, GoodError
  from zoo.orca.automl.search.parameters import DEFAULT_LOGGER_NAME, DEFAULT_METRIC_NAME
  from zoo.orca.automl.search.ray_tune.utils import convert_bayes_configs
  from zoo.orca.automl.search.utils import get_ckpt_hdfs, put_ckpt_hdfs
  from zoo.orca.automl.search import TensorboardLogger
  from ray.tune import Stopper
  from zoo.orca.automl.model.abstract import ModelBuilder
label_desc: Use image node_id 8 for calling the RayTuneSearchEngine obj's underlying member method code with example usage: obj.get_best_trials(k) and returns: unknown