class_docstr: Logical object for tracking Hyperband bracket progress. Keeps track
  of proper parameters as designated by HyperBand.
  
  Also keeps track of progress to ensure good scheduling.
class_docstr_tok: ["Logical","object","for","tracking","Hyperband","bracket","progress",".","Keeps","track","of","proper","parameters","as","designated","by","HyperBand",".","Also","keeps","track","of","progress","to","ensure","good","scheduling","."]
code: def current_trials(self) -> List[Trial]:
      return list(self._live_trials)
  
imports: import collections
  from typing import Dict, List, Optional, Tuple, TYPE_CHECKING
  import numpy
  import logging
  from ray.util.annotations import PublicAPI
  from ray.tune.result import DEFAULT_METRIC
  from ray.tune.schedulers.trial_scheduler import FIFOScheduler, TrialScheduler
  from ray.tune.experiment import Trial
  from ray.tune.error import TuneError
label_desc: Use image node_id 5 for calling the _Bracket obj's underlying member method code with example usage: obj.current_trials() and returns: list