code: def __len__(self):
      return len(self._indicators)
  
imports: from enum import Enum
  from pathlib import Path
  from typing import List, Optional, Tuple, NamedTuple, Dict, Union
  from labml import lab
  from labml.internal import util
  from labml.internal.experiment.experiment_run import RunInfo
  from labml.internal.util.strings import is_pattern_match
label_desc: Use image node_id 7 for calling the IndicatorCollection obj's underlying member method code with example usage: obj.__len__() and returns: len