class_docstr: Tune driver
code: def get_default_remote_dir(name):
      from bigdl.orca.ray import OrcaRayContext
      from bigdl.orca.automl.search.utils import process
  
      ray_ctx = OrcaRayContext.get()
      if ray_ctx.is_local:
          return None
      else:
          try:
              default_remote_dir = f"hdfs:///tmp/{name}"
              process(
                  command=f"hadoop fs -mkdir -p {default_remote_dir}; "
                  f"hadoop fs -chmod 777 {default_remote_dir}"
              )
              return default_remote_dir
          except Exception:
              return None
  
imports: import ray
  from ray import tune
  import os
  from bigdl.orca.automl.search.base import SearchEngine, TrialOutput, GoodError
  from bigdl.orca.automl.search.parameters import DEFAULT_LOGGER_NAME, DEFAULT_METRIC_NAME
  from bigdl.orca.automl.search.ray_tune.utils import convert_bayes_configs
  from bigdl.orca.automl.search.utils import get_ckpt_hdfs, put_ckpt_hdfs
  from ray.tune import Stopper
  from bigdl.orca.automl.model.abstract import ModelBuilder
  from bigdl.orca.data import ray_xshards
  from ray.tune.progress_reporter import TrialProgressCallback
  from bigdl.dllib.utils.log4Error import *
label_desc: Use image node_id 2 for calling the RayTuneSearchEngine obj's underlying member method code with example usage: obj.get_default_remote_dir(name) and returns: None, default_remote_dir, None