code: def update_ema(biased_ema: Tensor, current_val: Tensor, decay: float):
      """
      Exponential moving average method.
      """
      return biased_ema * decay + (1 - decay) * current_val
  
imports: from __future__ import annotations
  from typing import Dict, List, overload
  import torch
  from torch import Tensor
  from ..base.compressor import Compressor, Quantizer
  from ..base.wrapper import ModuleWrapper
  from ..utils import Evaluator, _EVALUATOR_DOCSTRING
label_desc: Use image node_id 2 for calling a global function with example usage: update_ema(biased_ema, current_val, decay) and returns: unknown