class_docstr: Standalone/tempdir exp queue implementation.
class_docstr_tok: ["Standalone\/tempdir","exp","queue","implementation","."]
code: def pid_dir(self) -> str:
      return os.path.join(self._standalone_tmp_dir, EXEC_PID_DIR)
  
imports: import os
  from collections import defaultdict
  from typing import TYPE_CHECKING, Collection, Dict, Generator, List, Optional
  from funcy import first
  from dvc.exceptions import DvcException
  from dvc.log import logger
  from dvc.repo.experiments.exceptions import ExpQueueEmptyError
  from dvc.repo.experiments.executor.base import ExecutorInfo, TaskStatus
  from dvc.repo.experiments.executor.local import TempDirExecutor
  from dvc.repo.experiments.utils import EXEC_PID_DIR, EXEC_TMP_DIR
  from dvc.utils.objects import cached_property
  from .base import BaseStashQueue, QueueEntry, QueueGetResult
  from .utils import fetch_running_exp_from_temp_dir
  from .workspace import WorkspaceQueue
label_desc: Use image node_id 2 for calling the TempDirQueue obj's underlying member method code with example usage: obj.pid_dir() and returns: os