code: def _update_target_stats(self, y, w):
      self._target_stats.update(y, w)
  
imports: from __future__ import annotations
  import collections
  import functools
  import io
  import math
  import typing
  from river import anomaly, base, drift, linear_model, stats
  from river.tree import split_criterion
  from river.tree import splitter
  from .base import HoeffdingRule
label_desc: Use image node_id 5 for calling the RegRule obj's underlying member method code with example usage: obj._update_target_stats(y, w) without return types