class_docstr: Computes a weighted average of model outputs with weights proportional to
  the metric values (or their inverses).
code: def _models_used(self) -> List[bool]:
      return CombinerBase._models_used.fget(self)
  
imports: from abc import abstractmethod
  from collections import OrderedDict
  import copy
  import logging
  from typing import List, Optional, Union
  import numpy
  from merlion.evaluate.anomaly import TSADMetric
  from merlion.evaluate.forecast import ForecastMetric
  from merlion.utils import UnivariateTimeSeries, TimeSeries
  from merlion.utils.misc import AutodocABCMeta
label_desc: Use image node_id 1 for calling the MetricWeightedMean obj's underlying member method code with example usage: obj._models_used() and returns: CombinerBase