class_docstr: Internal PBT state tracked per-trial.
class_docstr_tok: ["Internal","PBT","state","tracked","per-trial","."]
code: def __repr__(self) -> str:
      return str(
          (
              self.last_score,
              self.last_checkpoint,
              self.last_train_time,
              self.last_perturbation_time,
          )
      )
  
imports: import copy
  import json
  import logging
  import math
  import os
  import random
  import shutil
  import warnings
  from pathlib import Path
  from typing import Callable, Dict, List, Optional, Tuple, Union, TYPE_CHECKING
  from ray.air.constants import TRAINING_ITERATION
  from ray.train import Checkpoint
  from ray.train._internal.session import _TrainingResult, _FutureTrainingResult
  from ray.tune.error import TuneError
  from ray.tune.result import DEFAULT_METRIC
  from ray.tune.search import SearchGenerator
  from ray.tune.utils.util import SafeFallbackEncoder
  from ray.tune.search.sample import Domain, Function
  from ray.tune.schedulers import FIFOScheduler, TrialScheduler
  from ray.tune.search.variant_generator import format_vars
  from ray.tune.experiment import Trial
  from ray.util import PublicAPI
  from ray.util.debug import log_once
label_desc: Use image node_id 2 for calling the _PBTTrialState obj's underlying member method code with example usage: obj.__repr__() and returns: str